IBM Informix Developer's Handbook - IBM Redbooks

IBM Informix 

Developer’s Handbook 

Learn application development with 

supported APIs, drivers, and interfaces 

Understand Informix supported 

programming environments 

Follow practical examples to 

develop an Informix application 

ibm.com/redbooks 

Front cover 

Whei-Jen Chen 

Krishna Doddi 

Manoj Ghogale 

David Jay 

Javier Sagrera

International Technical Support Organization 

IBM Informix Developer’s Handbook 

October 2010 

SG24-7884-00

Note: Before using this information and the product it supports, read the information in 

“Notices” on page ix. 

First Edition (October 2010) 

This edition applies to IBM Informix Version 11.5. 

© Copyright International Business Machines Corporation 2010. All rights reserved. 

Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP 

Schedule Contract with IBM Corp.

Contents 

Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix 

Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x 

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi 

The team who wrote this book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi 

Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii 

Now you can become a published author, too! . . . . . . . . . . . . . . . . . . . . . . . . xiii 

Comments welcome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv 

Stay connected to IBM Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv 

Chapter 1. Introduction to IBM Informix . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

1.1 Server options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

1.1.1 Informix servers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

1.2 Informix tools for developers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

1.2.1 Informix Connect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

1.2.2 Informix Client Software Development Kit. . . . . . . . . . . . . . . . . . . . . . 9 

1.2.3 4GL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

1.2.4 Ruby on Rails . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

1.2.5 Informix DataBlade Developers Kit . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

1.2.6 Informix Spatial DataBlade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

1.2.7 PHP on Informix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

1.3 Informix overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

1.3.1 Architecture overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

1.3.2 Informix developer environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 

1.3.3 Informix capabilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 

Chapter 2. Setting up an Informix development environment . . . . . . . . . 25 

2.1 Server setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 

2.1.1 Planning for the installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 

2.1.2 Installing Informix Server. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 

2.1.3 Configuring Informix Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 

2.2 Client setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 

2.2.1 Informix Client options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 

2.2.2 Installing and setting up Client SDK . . . . . . . . . . . . . . . . . . . . . . . . . 36 

2.2.3 Setting up IBM Data Server drivers. . . . . . . . . . . . . . . . . . . . . . . . . . 43 

2.2.4 Setting up Informix JDBC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 

Chapter 3. Working with the ODBC driver . . . . . . . . . . . . . . . . . . . . . . . . . 57 

3.1 ODBC and Informix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 

© Copyright IBM Corp. 2010. All rights reserved. iii

3.2 Setup and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 

3.2.1 IBM Informix ODBC Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 

3.2.2 IBM Data Server Driver for ODBC and CLI. . . . . . . . . . . . . . . . . . . . 70 

3.2.3 Verifying connectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 

3.3 Developing an ODBC application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 

3.3.1 Connecting to the database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 

3.3.2 Type mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 

3.3.3 Performing database operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 

3.3.4 Handling special data types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 

3.3.5 Error handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 

3.3.6 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 

Chapter 4. Working with ESQL/C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 

4.1 Informix ESQL/C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 

4.2 Setup and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 

4.3 Windows system configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 

4.4 Developing an ESQL/C application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 

4.4.1 Creating an ESQL/C application . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 

4.4.2 Performing database operations . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 

4.4.3 Data types mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 

4.4.4 Handling special data types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 

4.4.5 Exception handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 


Chapter 5. Working with the JDBC drivers . . . . . . . . . . . . . . . . . . . . . . . . 153 

5.1 JDBC drivers for an Informix database . . . . . . . . . . . . . . . . . . . . . . . . . . 154 

5.1.1 IBM Informix JDBC Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 

5.1.2 IBM Data Server Driver for JDBC and SQLJ . . . . . . . . . . . . . . . . . 156 


5.2.1 Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 

5.2.2 Verify connectivity with Informix JDBC Driver . . . . . . . . . . . . . . . . . 158 

5.2.3 Verify connectivity with the Data Server Driver . . . . . . . . . . . . . . . . 160 

5.3 JDBC type mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 

5.4 Performing database operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 

5.4.1 Connection to the database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 

5.4.2 Manipulating data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 

5.5 Informix additional features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 

5.5.1 Batch inserts or updates and using ResultSet metadata . . . . . . . . 175 

5.5.2 BIGSERIAL data type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 

5.5.3 Informix smart large objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 

5.5.4 Secure Socket Layer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 

5.6 Typical errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 

5.6.1 Class not found errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 

iv IBM Informix Developer’s Handbook

5.6.2 Connectivity errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 

5.6.3 Syntax errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 

5.7 Tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 

5.7.1 IBM Informix JDBC Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 

5.7.2 IBM Data Server Driver for JDBC . . . . . . . . . . . . . . . . . . . . . . . . . . 188 

Chapter 6. IBM Informix with Hibernate . . . . . . . . . . . . . . . . . . . . . . . . . . 189 

6.1 Hibernate for Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 

6.1.1 Overview of Hibernate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 

6.1.2 Hibernate concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 


6.2.1 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 

6.2.2 Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 

6.3 Using Hibernate with an Informix database. . . . . . . . . . . . . . . . . . . . . . . 198 

6.3.1 Components of a Hibernate application . . . . . . . . . . . . . . . . . . . . . 198 

6.3.2 Working with a Hibernate object . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 

6.3.3 Using annotations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 

Chapter 7. Working with IBM Informix OLE DB Provider. . . . . . . . . . . . . 215 

7.1 IBM Informix OLE DB Provider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 


7.2.1 Installation and setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 

7.2.2 Verifying connectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 

7.3 Developing an OLE DB application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 

7.3.1 Supported interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 

7.3.2 Connecting to database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 

7.3.3 Type mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 

7.3.4 Cursors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 

7.3.5 Typical database operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 

7.4 Visual Basic, ADO.NET, and SQL Server . . . . . . . . . . . . . . . . . . . . . . . . 237 

7.4.1 OLE DB with Visual Basic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 

7.4.2 ADO.NET and the OLEDB bridge . . . . . . . . . . . . . . . . . . . . . . . . . . 240 

7.4.3 SQL Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 

7.5 Troubleshooting and tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 

7.5.1 Typical errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 

7.5.2 Tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 

Chapter 8. Working with .NET data providers. . . . . . . . . . . . . . . . . . . . . . 253 

8.1 Informix and .NET data providers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 


8.2.1 IBM Informix .Net Provider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 

8.2.2 IBM Data Server Provider for .NET. . . . . . . . . . . . . . . . . . . . . . . . . 255 


8.3 Developing a .NET application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 

Contents v

8.3.1 Connecting to the database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 

8.3.2 Data type mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 


8.3.4 Handling Informix specific data types . . . . . . . . . . . . . . . . . . . . . . . 276 


8.3.6 Tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 

8.4 Visual Studio Add-In for Visual Studio. . . . . . . . . . . . . . . . . . . . . . . . . . . 293 

Chapter 9. Working with PHP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 

9.1 Informix and PHP extensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 


9.2.1 Installing OAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 

9.2.2 Verifying the PDO_INFORMIX setup . . . . . . . . . . . . . . . . . . . . . . . 299 

9.2.3 Verifying the PDO setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 


9.3 Developing a PHP application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 

9.3.1 Connecting to a database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 


9.3.3 Handling complex data types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 

9.3.4 Working with PHP extensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 

9.3.5 Exception handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 


Chapter 10. User-defined routines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 

10.1 An overview of UDRs and database extensions . . . . . . . . . . . . . . . . . . 330 

10.1.1 Considerations for UDRs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 

10.1.2 About UDRs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 

10.1.3 Considerations for extending data types. . . . . . . . . . . . . . . . . . . . 334 

10.2 Developing UDRs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 

10.2.1 UDR examples in SQL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 

10.2.2 UDRs in Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 

10.2.3 UDRs in C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 

10.3 DataBlades and bladelets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352 

10.3.1 Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 

10.3.2 IBM Informix provided DataBlades . . . . . . . . . . . . . . . . . . . . . . . . 357 

10.3.3 Developing a bladelet routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 

Chapter 11. Working with Ruby on Rails. . . . . . . . . . . . . . . . . . . . . . . . . . 361 

11.1 A brief overview of Ruby on Rails . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 

11.1.1 Architecture of Ruby on Rails . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 

11.1.2 Ruby Driver and Rails Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 

11.2 Setup and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 

11.2.1 Ruby Informix driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 

11.2.2 Data Server Ruby driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 

vi IBM Informix Developer’s Handbook

11.2.3 Rails adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 

11.3 Database operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373 

11.4 Using the Rails Adapter with Ruby Informix . . . . . . . . . . . . . . . . . . . . . 384 

11.4.1 Creating database objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384 

11.4.2 Creating the Rails application . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385 

11.4.3 Modifying the database configuration file . . . . . . . . . . . . . . . . . . . 386 

11.4.4 Creating the Rails model and controllers . . . . . . . . . . . . . . . . . . . 387 

11.4.5 Starting the Rails web server . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389 

11.4.6 Demonstrating website application . . . . . . . . . . . . . . . . . . . . . . . . 389 

11.5 Using the Rails Adapter with IBM_DB. . . . . . . . . . . . . . . . . . . . . . . . . . 391 

11.5.1 Creating the Rails application . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392 

11.5.2 Modifying the database configuration file . . . . . . . . . . . . . . . . . . . 392 

11.5.3 Creating model, control, and view. . . . . . . . . . . . . . . . . . . . . . . . . 393 

11.5.4 Migrating the model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 

11.5.5 Starting the Rails web server . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396 

11.5.6 Checking the application from website . . . . . . . . . . . . . . . . . . . . . 396 

Chapter 12. Informix 4GL Web Services . . . . . . . . . . . . . . . . . . . . . . . . . . 399 

12.1 Basic concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 

12.1.1 IBM Informix 4GL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 

12.1.2 Service-oriented architecture and Web Services . . . . . . . . . . . . . 400 

12.1.3 Web Services development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 

12.1.4 Informix 4GL and Web Services . . . . . . . . . . . . . . . . . . . . . . . . . . 401 

12.1.5 Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401 

12.2 Setup and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402 

12.2.1 Prerequisites and supported platforms . . . . . . . . . . . . . . . . . . . . . 402 

12.2.2 Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403 

12.3 Informix 4GL Web Services tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404 

12.3.1 The w4glc Web Services compiler . . . . . . . . . . . . . . . . . . . . . . . . 404 

12.3.2 The w4gl utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406 

12.3.3 Web Services Description Language Parser (wsdl_parser) . . . . . 407 

12.3.4 I4GL Web Services process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409 

12.4 Developing a web service with I4GL . . . . . . . . . . . . . . . . . . . . . . . . . . . 409 

12.4.1 Example I4GL function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410 

12.4.2 Host and application details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411 

12.4.3 Definition of the web service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412 

12.4.4 Generate the configuration file . . . . . . . . . . . . . . . . . . . . . . . . . . . 416 

12.4.5 Deployment of the web service . . . . . . . . . . . . . . . . . . . . . . . . . . . 420 

12.4.6 Packaging of the web service . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421 

12.4.7 Starting the Axis2 application server. . . . . . . . . . . . . . . . . . . . . . . 422 

12.4.8 Consuming the I4GL web service . . . . . . . . . . . . . . . . . . . . . . . . . 422 

12.5 Consuming a web service with I4GL . . . . . . . . . . . . . . . . . . . . . . . . . . . 425 

12.5.1 Web service to consume. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425 

Contents vii

12.5.2 Compiling the wrapper code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427 

12.5.3 Using the web service from an I4GL application. . . . . . . . . . . . . . 428 

12.6 Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 

12.6.1 Typical problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 

12.6.2 Tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 

Chapter 13. Application development considerations. . . . . . . . . . . . . . . 437 

13.1 Concurrency and locking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438 

13.1.1 Types of locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438 

13.1.2 Lock duration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440 

13.1.3 Lock granularity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440 

13.2 Locking issues and performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445 

13.2.1 Deadlocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446 

13.3 Isolation levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447 

13.4 Configuration options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449 

13.4.1 Server identification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449 

13.4.2 Storage space identifiers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 

13.4.3 Limiters and limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452 

13.4.4 Java configuration parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 

13.5 Working with your database administrator . . . . . . . . . . . . . . . . . . . . . . 458 

13.5.1 Parameters for negotiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461 

13.5.2 Monitoring isolation levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 

13.5.3 Monitoring locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463 

13.5.4 Monitoring user threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464 

Appendix A. Parameters in the onconfig file . . . . . . . . . . . . . . . . . . . . . . 467 

Appendix B. Accommodating distributed transactions . . . . . . . . . . . . . 469 

B.1 Distributed transactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 470 

B.2 TP/XA Transaction Manager XA Interface Library . . . . . . . . . . . . . . . . . 470 

B.3 XA_TOOL ESQL/C sample. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471 

Related publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 479 

IBM Redbooks publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 479 

Other publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 479 

Online resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480 

How to get IBM Redbooks publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480 

Help from IBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480 

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481 

viii IBM Informix Developer’s Handbook

Notices 

This information was developed for products and services offered in the U.S.A. 

IBM may not offer the products, services, or features discussed in this document in other countries. Consult 

your local IBM representative for information on the products and services currently available in your area. 

Any reference to an IBM product, program, or service is not intended to state or imply that only that IBM 

product, program, or service may be used. Any functionally equivalent product, program, or service that 

does not infringe any IBM intellectual property right may be used instead. However, it is the user's 

responsibility to evaluate and verify the operation of any non-IBM product, program, or service. 

IBM may have patents or pending patent applications covering subject matter described in this document. 

The furnishing of this document does not give you any license to these patents. You can send license 

inquiries, in writing, to: 

IBM Director of Licensing, IBM Corporation, North Castle Drive, Armonk, NY 10504-1785 U.S.A. 

The following paragraph does not apply to the United Kingdom or any other country where such 

provisions are inconsistent with local law: INTERNATIONAL BUSINESS MACHINES CORPORATION 

PROVIDES THIS PUBLICATION "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR 

IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, 

MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Some states do not allow disclaimer 

of express or implied warranties in certain transactions, therefore, this statement may not apply to you. 

This information could include technical inaccuracies or typographical errors. Changes are periodically made 

to the information herein; these changes will be incorporated in new editions of the publication. IBM may 

make improvements and/or changes in the product(s) and/or the program(s) described in this publication at 

any time without notice. 

Any references in this information to non-IBM websites are provided for convenience only and do not in any 

manner serve as an endorsement of those websites. The materials at those websites are not part of the 

materials for this IBM product and use of those websites is at your own risk. 

IBM may use or distribute any of the information you supply in any way it believes appropriate without 

incurring any obligation to you. 

Information concerning non-IBM products was obtained from the suppliers of those products, their published 

announcements or other publicly available sources. IBM has not tested those products and cannot confirm 

the accuracy of performance, compatibility or any other claims related to non-IBM products. Questions on 

the capabilities of non-IBM products should be addressed to the suppliers of those products. 

This information contains examples of data and reports used in daily business operations. To illustrate them 

as completely as possible, the examples include the names of individuals, companies, brands, and products. 

All of these names are fictitious and any similarity to the names and addresses used by an actual business 

enterprise is entirely coincidental. 

COPYRIGHT LICENSE: 

This information contains sample application programs in source language, which illustrate programming 

techniques on various operating platforms. You may copy, modify, and distribute these sample programs in 

any form without payment to IBM, for the purposes of developing, using, marketing or distributing application 

programs conforming to the application programming interface for the operating platform for which the 

sample programs are written. These examples have not been thoroughly tested under all conditions. IBM, 

therefore, cannot guarantee or imply reliability, serviceability, or function of these programs. 

© Copyright IBM Corp. 2010. All rights reserved. ix

Trademarks 

IBM, the IBM logo, and ibm.com are trademarks or registered trademarks of International Business 

Machines Corporation in the United States, other countries, or both. These and other IBM trademarked 

terms are marked on their first occurrence in this information with the appropriate symbol (® or ), 

indicating US registered or common law trademarks owned by IBM at the time this information was 

published. Such trademarks may also be registered or common law trademarks in other countries. A current 

list of IBM trademarks is available on the Web at http://www.ibm.com/legal/copytrade.shtml 

The following terms are trademarks of the International Business Machines Corporation in the United States, 

other countries, or both: 

AIX® 

DataBlade® 

DB2 Universal Database 

DB2® 

developerWorks® 

x IBM Informix Developer’s Handbook 

Distributed Relational Database 

Architecture 

DRDA® 

IBM® 

Informix® 

MQSeries® 

The following terms are trademarks of other companies: 

Rational® 

Redbooks® 

Redpaper 

Redbooks (logo) ® 

UC2 

WebSphere® 

Java, and all Java-based trademarks are trademarks of Sun Microsystems, Inc. in the United States, other 

countries, or both. 

Microsoft, Windows, and the Windows logo are trademarks of Microsoft Corporation in the United States, 

other countries, or both. 

UNIX is a registered trademark of The Open Group in the United States and other countries. 

Linux is a trademark of Linus Torvalds in the United States, other countries, or both. 

Other company, product, or service names may be trademarks or service marks of others.

Preface 

IBM® Informix® is a low-administration, easy-to-use, and embeddable database 

that is ideal for application development. It supports a wide range of development 

platforms, such as Java, .NET, PHP, and web services, enabling developers to 

build database applications in the language of their choice. Informix is designed 

to handle RDBMS data and XML without modification and can be extended 

easily to handle new data sets. 

This IBM Redbooks® publication provides fundamentals of Informix application 

development. It covers the Informix Client installation and configuration for 

application development environments. It discusses the skills and techniques for 

building Informix applications with Java, ESQL/C, OLE DB, .NET, PHP, Ruby on 

Rails, DataBlade®, and Hibernate. 

The book uses code examples to demonstrate how to develop an Informix 

application with various drivers, APIs, and interfaces. It also provides application 

development troubleshooting and considerations for performance. 

This book is intended for developers who use IBM Informix for application 

development. Although some of the topics that we discuss are highly technical, 

the information in the book might also be helpful for managers or database 

administrators who are looking to better understand their Informix development 

environment. 

The team who wrote this book 

This book was produced by a team of specialists from around the world working 

at the International Technical Support Organization, Rochester Center. 

Whei-Jen Chen is a Project Leader at the International Technical Support 

Organization, San Jose Center. She has extensive experience in application 

development, database design and modeling, and DB2® system administration. 

Whei-Jen is an IBM Certified Solutions Expert in Database Administration and 

Application Development, and an IBM Certified IT Specialist 

© Copyright IBM Corp. 2010. All rights reserved. xi

Krishna Doddi (also known as Prasad) has been with IBM 

Informix since 1996. He worked in Informix Advanced Support 

for Client Products. The main products he supported were 

Informix Client Software Development Kit (Client SDK), mostly 

on the Microsoft Windows® platform. After the IBM acquisition 

in 2001, he moved to DB2 Advanced Support, again in the 

Client Products division. After five years in DB2, he moved to 

Informix QA for Informix Client products, including JCC 

Common Client and PureQuery. He is currently the contact for Informix 

Integration projects. 

xii IBM Informix Developer’s Handbook 

Manoj Ghogale is a Tech Lead in the Informix team at ISL 

India. Manoj has 9 years of industry experience and has been 

with IBM for 5 years. He has worked on numerous automation 

projects and new features of Informix Server. He holds a 

Bachelor's degree in Engineering from National Institute of 

Engineering, Mysore, India. 

David Jay is a Staff Software Engineer in the IBM North 

Americas Technical Support Team, providing advanced 

technical support, defect discovery, and support training for 

Informix products and SolidDB. David joined the Informix 

Support team in September 1996, and has served in various 

software and support roles since the 1980’s. He has a 

Bachelor of Science from Pennsylvania State University, and 

enjoys public speaking assignments whenever he gets them 

through Toastmasters and IBM. 

Javier Sagrera is a software engineer on the Common Client 

Technologies (CCT) group. He joined the Informix team in 2000 

and has over 15 years experience in application development 

for Informix database servers and Informix clients. Currently 

based on the IBM UK Bedfont Lab in London, he has extensive 

knowledge on all the Microsoft® technologies and is 

considered as a subject matter expert worldwide on all the 

Informix development tools.

Acknowledgements 

Thanks to the following people for their contributions to this project: 

Jacques Roy 

Ted Wasserman 

Rakeshkumar Naik 

Jonathan Leffler 

Robert Uleman 

Richard Snoke 

Guy Bowerman 

IBM Software Group 

Greg Holmes 

Alberto Bortolan 

Adam Hattrell 

IBM Bedfont Laboratory 

Emma Jacobs 

International Technical Support Organization, Rochester Center 

Now you can become a published author, too! 

Here’s an opportunity to spotlight your skills, grow your career, and become a 

published author—all at the same time! Join an ITSO residency project and help 

write a book in your area of expertise, while honing your experience using 

leading-edge technologies. Your efforts will help to increase product acceptance 

and customer satisfaction, as you expand your network of technical contacts and 

relationships. Residencies run from two to six weeks, and you can participate 

either in person or as a remote resident working from your home base. 

Find out more about the residency program, browse the residency index, and 

apply online at: 

ibm.com/redbooks/residencies.html 

Preface xiii

Comments welcome 

Your comments are important to us! 

We want our books to be as helpful as possible. Send us your comments about 

this book or other IBM Redbooks publications in one of the following ways: 

► Use the online Contact us review Redbooks form found at: 


► Send your comments in an email to: 

redbooks@us.ibm.com 

► Mail your comments to: 

IBM Corporation, International Technical Support Organization 

Dept. HYTD Mail Station P099 

2455 South Road 

Poughkeepsie, NY 12601-5400 

Stay connected to IBM Redbooks 

► Find us on Facebook: 

http://www.facebook.com/IBMRedbooks 

► Follow us on Twitter: 

http://twitter.com/ibmredbooks 

► Look for us on LinkedIn: 

http://www.linkedin.com/groups?home=&gid=2130806 

► Explore new Redbooks publications, residencies, and workshops with the 

IBM Redbooks weekly newsletter: 

https://www.redbooks.ibm.com/Redbooks.nsf/subscribe?OpenForm 

► Stay current on recent Redbooks publications with RSS Feeds: 

http://www.redbooks.ibm.com/rss.html 

xiv IBM Informix Developer’s Handbook

1 

Chapter 1. Introduction to IBM Informix 

We live in a business world that requires a variety of software components to fully 

handle the scope of business needs. When considered as a group, the products 

have to work together, and they must scale well to cover the demands of 

business to assure continued growth. Frequently, a significant criteria list might 

be needed to specify all the facets that are encountered in daily, monthly, and 

yearly periods of business operations. Developers must be sensitive to how the 

database engine functions, what server-side capabilities can be brought into 

play, and what development tasks need to occur on the client or application side. 

In this chapter, we provide an overview of Informix products and capabilities. Our 

approach is somewhat reference oriented. In addition to the overview of Informix 

products, we also provide an awareness of the architecture of IBM Informix from 

both the server-side and the client-side, to better acquaint the developer with 

perspectives that you might need to know. 

We also discuss the capabilities of the products in the Informix suite. The IBM 

Informix products that we describe demonstrate how to manage business 

performance, handle all types of business applications, minimize administration 

through various self-automated and self-monitored options and, at all times, 

optimize the setup to help minimize costs for maintenance and resource 

allocations. 

© Copyright IBM Corp. 2010. All rights reserved. 1

1.1 Server options 

There are a number of options for IBM Informix servers that are designed to meet 

the needs of business enterprises that range in size from a small group with a 

few employees up to several thousand people. The database needs to meet a 

variety of requirements of a diverse group. This section includes a brief 

discussion of each of the server possibilities and how they are generally used. 

With the wealth of different server types available, unless otherwise noted, each 

comes with the opportunity to use the IBM Informix Client Software Development 

Kit (Client SDK) for development of applications. Prior to renaming the brand 

editions in May 2010, IBM Informix had several versions. You can expect that 

each version is backward and forward compatible, beginning with 7.2x and 

moving forward through 7.3x, 9.2x, 9.30, 9.40, and 10.00. The Cheetah series 

began with Informix Dynamic Server 11.10 and quickly advanced into the 11.50 

family. At this writing, the IBM Informix Ultimate series is now available, which 

begins with 11.50.xC7 and following. 

It is helpful to be aware of version numbering conventions: 

► The letters UC or UD at the end of a version number indicate 32-bit UNIX®. 

► The letters TC indicate a 32-bit Windows version. 

► The letters FC indicate a 64-bit version (UNIX or Windows). 

1.1.1 Informix servers 

These naming conventions become important in application and memory 

addressability. A 32-bit application works with a 64-bit server, but the application 

can access only 32-bit memory. 

Several options are available for IBM Informix servers. Each option is designed to 

address specific needs in business. This section discusses these different 

options. 

No-charge editions 

The following no-charge editions are available as separate offerings subject to 

the IBM International License Agreement for Non-Warranted Programs (ILAN): 

► Informix Developer Edition 

► Informix Innovator-C Edition 

2 IBM Informix Developer’s Handbook

Informix Developer Edition 

The Informix Developer Edition provides all the features of Informix at no cost, 

when used solely for application development and testing. It can be used for 

application development and prototyping with no time limits. Support is available 

by way of the Informix user community through Internet forums. 

Informix Developer Edition offers the following application development choices: 

► C 

► C++ 

► .NET 

► Java 

► Ruby on Rails 

► Perl 

► Python 

► PHP 

► 4GL 

Informix Developer Edition supports the following operating systems: 

► AIX® 

► HP 

► UNIX 

► Linux® 

► Macintosh 

► Sun Solaris 

► Windows 

This Informix edition is limited to 1 CPU, 1 GB memory, and 8 GB storage. 

Informix Developer Edition includes the following bundle: 

► Informix Client Software Development Kit 

► Informix DataBlade Developers Kit 

► Informix Spatial Datablade 

Informix Innovator-C Edition 

The Innovator-C Edition provides a robust and powerful environment that is 

designed to support small production workloads. It features the most widely used 

data processing functionality, including limited Enterprise Replication and high 

availability clustering. 

Chapter 1. Introduction to IBM Informix 3

This edition offers the following application development choices: 

► C 

► C++ 

► .NET 

► Java 

► Ruby on Rails 

► Perl 

► 4GL 

Innovator-C Edition supports the following operating systems: 

► AIX 

► HP 

► UNIX 

► Linux 

► Macintosh 


► Windows 

This edition is limited to one socket with no more than four cores and with a total 

of 2 GB of RAM that are operating from the same installation. 

Note: Innovator-C Edition is an offering to be used for development, test, and 

user production workloads without a license fee. This edition can be used only 

by user organizations. It cannot be redistributed without signing a 

redistribution contract. Support is community-based though an optional 

for-charge service and support package is available. 

Licensed versions 

In a business enterprise that demands constant uptime and consistent delivery 

requirements, it helps to have a license and professional, timely support to cover 

every need. There are several licensing options available. 

In this section, we discuss the Informix Server versions that are licensed 

subscriptions. Table 1-1 describes the terms and abbreviations for these editions. 

The criteria might be subject to change over time. Consult with a sales 

representative for the most accurate definitions. 


Table 1-1 Informix licensed versions 

Licensing term Defined 

Processor Value Unit 

(PVU) 

(also known as processor-based 

pricing) 

Authorized User 

Single Install 

Calculated using the number of processor cores in the physical server 

multiplied by the corresponding value units based on processor 

architecture. An unlimited user or connection license and is usually 

the optimal choice when the user or session load cannot be controlled 

or counted. 

A single named user or specific individual accessing one installation 

of Informix on each physical or virtual server. That authorized user can 

establish multiple connections to an Informix instance on the server. 

Each connection is for the exclusive use of that one authorized user 

from a single client device. 

Concurrent Session A single logical connection from a client device to an Informix instance 

on each physical or logical server. Each connection, whether active or 

not, requires a license, regardless of whether it comes from one client 

device with multiple users or from a single user establishing multiple 

connections. The number of concurrent sessions is counted from the 

client device, rather than at the server level, regardless of whether the 

connection is directly to the Informix instance or indirectly or whether 

it is through application servers, persistent connectivity layers, 

connection multiplexers or concentrators, or any other technology 

inserted between the actual user and the Informix instance. 

Limited Use Socket 

(LU Socket) 

Available only on Informix Growth Edition, this license allows for 

licensing on a physical socket potentially containing multiple cores. A 

LU Socket license is required for each active processor socket. This 

licensing metric can be used only on a physical server with no more 

than four physical sockets. You can purchase licenses for up to four 

physical sockets and use up to 16 cores. 

Install An “Install” is an installed copy of an Informix product on a physical 

server (or partition thereof) or in a virtual machine image. For 

example, if a physical server is segmented into partitions, whether 

logical (also know as LPARs) or physical, each partition containing 

Informix is considered a separate IBM Informix “Install” for licensing 

purposes and restrictions. The concept of an “Install” applies to the 

licensing limits specified for all Informix Editions. 

Informix Choice Edition 

Informix Choice Edition is ideal for small to medium size business. This edition is 

available for both Microsoft Windows and Apple Macintosh operating systems. 

This edition is limited to a total of eight cores over a maximum of two sockets and 

8 GB of RAM operating. The Informix Choice Edition includes limited Enterprise 

Replication (ER) clustering with 2-root nodes to send or receive data updates 

within the cluster. This edition also provides limited high availability (HA) cluster 

functionality. Along with the primary server, you can have one secondary node, 


either an HDR secondary or RSS secondary. The HA cluster secondary node 

can be used for SQL operations. This edition does not support use of the Shared 

Disk secondary (SD secondary) node type. 

Informix Growth Edition 

The Informix Growth Edition is available on all platforms (Linux, UNIX, Windows, 

and Apple Macintosh). The Growth Edition is ideal for mid-sized companies or 

departmental servers in an enterprise deployment. It can be deployed on up to 

16 cores over a maximum of four sockets and 16 GB of RAM operating from the 

same Install. License options include Authorized User Single Install, Concurrent 

Session, PVU, and LU Socket metrics. LU Socket enables licensing by physical 

processor socket and is limited to physical servers with no more than four 

physical processor sockets. 

Informix Growth Edition gives you additional database functionality, including 

unlimited ER cluster nodes of any type for sending or receiving data updates 

within the cluster. From a licensing perspective, because ER nodes are 

stand-alone, each ER node must be fully licensed. Informix Growth edition 

supports up to two HA cluster secondary nodes of any type. As long as the 

secondary node or nodes are functioning only as a backup secondary, they can 

be deployed without charge. However, if you use a secondary node for SQL 

operations (read or write), the secondary node must be fully licensed. 

Informix Ultimate Edition 

The IBM Informix Ultimate Edition includes nearly all the Informix features and 

functionality with unlimited scalability required for the highest OLTP and 

warehousing performance. 

Informix Ultimate Edition supports the following operating systems: 

► AIX 

► HP 

► UNIX 

► Linux 

► Macintosh 


► Windows 

This edition can be licensed by PVU, Concurrent Session, or Authorized User 

Single Install metrics. 

With this edition, full HA cluster and ER functionality is available, including 

unlimited ER nodes and all HA cluster secondary instance types. From a 

licensing perspective, because ER nodes are stand-alone, each ER node must 

be fully licensed, but HA secondary nodes can be deployed without charge if they 


are functioning only as a backup secondary. If you use any secondary node for 

SQL operations (read or write), the secondary node must be fully licensed. 

This edition offers the Geodetic and Excalibur DataBlades add-on. 

The Storage Optimization Feature was released with Informix version11.5 xC4 

and following. The Storage Optimization Feature provides data compression to 

dramatically reduce data storage and backup/recovery costs and administration. 

The reduced data footprint also provides a significant increase in performance for 

data retrieval. 

Extended Parallel Server 

The IBM Informix Extended Parallel Server is a high-end database that is 

typically used for scalable data warehousing with fast data loading and 

comprehensive data management. It is designed for a broad range of enterprises 

that require complex, query-intensive analytical applications. 

IBM Informix Extended Parallel Server uses the following examples: 

► Reliable data manipulation 

► Ad hoc queries from data warehouses 

► A combined data warehouse and data mart 

► Rapid and concurrent data loading and query execution 

IBM Informix Extended Parallel Server provides full parallel query processing, 

while being able to use hardware resources to deliver mainframe-caliber 

scalability, manageability, and performance with minimal OS and administrative 

overhead. For more information, see Database Strategies: Using Informix XPS 

and DB2 Universal Database, SG24-6437. 

Informix OnLine 

IBM Informix OnLine is an easy to use, embeddable relational database server 

for low-to-medium workloads. 

It has less features and functionality than the Informix Ultimate Server, but it 

scales well while providing online transaction processing support and the 

assurance of data integrity. Informix OnLine has rich multimedia data 

management capabilities, supporting the storage of a wide range of media such 

as documents, images, and audio by way of text and byte columns. Also, it is not 

designed to handle extended data types or replication. 

This server supports a wide variety of application development tools, along with a 

large number of other third-party tools, through support for the ODBC and JDBC 

industry standards for client connectivity. 


There are three edition options for this server: 

► Informix OnLine Extended Edition 5.20 

This edition option is a full-featured, easy-to-use SQL database with low 

administrative overhead. It contains two popular Informix products, Informix 

OnLine and Informix STAR, and provides distributed computing with a proven 

database server. It allows the Rapid Application Development tools to use 

pipes to communicate with OnLine Extended Edition 5.20 servers running on 

the same system, instead of having to use a TCP/IP loopback connection with 

Informix Star or Informix Net. It supports greater than 2 GB chunk offsets, to 

use the entire capacity of the disk drive without partitioning it into smaller 

logical devices and employing logical volume managers. 

The operating systems this edition supports include AIX, HP UNIX, and Sun 

Solaris. 

► Informix OnLine Extended Edition for Linux 

This edition is same as the Informix OnLine Extended Edition 5.20 but is but 

only available for Linux. 

► Informix OnLine Personal Edition 

This is the single-user product version, available only on Linux. It provides the 

same functionality as IBM Informix OnLine Extended Edition, at an 

economical cost. It enables you to quickly become familiar with the 

ease-of-use and multimedia capability of this proven relational database 

management system. 

Standard Engine 

IBM Informix Standard Engine is an embeddable database server that runs on 

UNIX, Linux and Windows. It provides an ideal solution for developing small to 

medium-sized applications that need the power of SQL without database 

administration requirements (low-maintenance, high-reliability). For limited scale 

databases, it delivers excellent performance, adheres to data consistency 

standards, and still provides client/server capabilities. It can be seamlessly 

integrated with Informix application development tools and third-party 

development tools compliant with the ODBC and JDBC standards. 

This edition supports the following operating systems: 

► AIX 

► HP UNIX 

► Linux 


► Windows 


1.2 Informix tools for developers 

There is a significant list of tools available from Informix for developers. We focus 

on the available application programming interface (API) options and language 

possibilities. There are also other utilities and tools that are provided with the 

engine that promote further ease of use. 

The 4GL developer’s edition includes the ACE Report Writer, which can be used 

to generate forms and reports quickly. The High Performance Loader, onload, 

onunload, and External table are bulk load and unload utilities that provide fast 

flat file movements. Other tools include I-Spy for auditing, MaxConnect, and the 

OpenAdmin Tool (OAT) for remote server administration and SQL. 

For more information about these or other tools, consult with a sales 

representative or visit the Informix support website at: 

http://www-947.ibm.com/support/entry/portal/Overview/Software/Information_Manag 

ement/Informix_Product_Family 

1.2.1 Informix Connect 

Informix Connect is the run time version of Client SDK that comes with the server 

engine. You use Client SDK and related tools to develop your application. When 

it is ready for use in production, Informix Connect is the tool used to deploy the 

application. It is supplied with the server engine software and provides the 

connectivity and runtime libraries which permit interaction between the engine 

and the application. While some Informix Connect development can be done 

without Client SDK, the great majority should be handled through the Client SDK 

API. 

1.2.2 Informix Client Software Development Kit 

Client SDK is a package of several APIs that are optimized for developing 

applications for IBM Informix servers. Client SDK allows developers to write 

applications in the language they prefer and to build applications that can access 

multiple IBM Informix databases. In this section, we discuss the API packages 

that are included in Client SDK. 

Open Database Connectivity 

Open Database Connectivity (ODBC) is a specification for a database API. It is 

based on the Call Level Interface specifications from X/Open and the 

International Standards Organization and International Electromechanical 

Commission (ISO/IEC). ODBC supports SQL statements with a library of C 


functions. An application calls these functions to implement ODBC functionality. 

ODBC applications can perform the following operations: 

► Connect to and disconnect from data sources. 

► Retrieve information about data sources. 

► Retrieve information about the IBM Informix ODBC Driver. 

► Set and retrieve IBM Informix ODBC Driver options. 

► Prepare and send SQL statements. 

► Retrieve SQL results and process the results dynamically. 

► Retrieve information about SQL results and process the information 

dynamically. 

ODBC lets you allocate storage before or after the SQL results are available.This 

feature lets you determine the results and the action to take without the 

limitations that predefined data structures impose. ODBC does not require a 

preprocessor to compile an application program. ODBC supports Secure 

Sockets Layer (SSL) connections. For information about using the SSL protocol, 

see IBM Informix Version 11.5 Security Guide, SC23-7754. 

Informix ODBC supports the following additional features and capabilities: 

► Microsoft Transaction Server (MTS) environment. For more information about 

MTS, see the MTS sections in IBM Informix ODBC Driver Programmers 

Manual, SC23-9423. 

► ODBC can handle extended data types such as: 

– Collection (LIST, MULTISET, and SET) 

– Distinct 

– Opaque (fixed, unnamed) 

– Row (named, unnamed) 

– Smart large objects (BLOB and CLOB) 

– Client functions that support extended data types 

► Long identifiers 

► Global Language Support (GLS) data types (NCHAR,NVARCHAR). 

► Support for Unicode and XA. 

► IPv6 internet protocol. 


ODBC with the IBM Informix ODBC Driver can include the following 

components: 

► Driver manager 

An application can link to a driver manager that links to the driver specified by 

the data source. The driver manager also checks parameters and transitions. 

You can purchase the ODBC Driver Manager from a third-party vendor for 

most UNIX platforms. On Microsoft Windows platforms, the ODBC Driver 

Manager is a part of the Operating System. 

► IBM Informix ODBC Driver 

This driver provides an interface to the Informix database server. Applications 

can use the driver in the following configurations: 

– To link to the ODBC driver manager 

– To link to the Driver Manager Replacement and the driver 

– To link to the driver directly 

► Data sources 

The driver provides access to the following data sources: 

– Database management systems (DBMS) and database servers 

– Databases 

– Operating systems and network software required for accessing the 

database 

JDBC and SQLJ 

JDBC is an application programming interface (API) that Java applications use to 

access relational databases. IBM Informix database systems can be supported 

by one of two APIs for client applications and applets written in Java: 

► IBM Data Server Driver 

You can use the IBM Data Server Driver (also known as the IBM common 

client driver) with either DB2 or Informix. This JDBC driver lets you write Java 

applications to access a local Informix Server, DB2 data, or any remote 

relational data on a server that supports DRDA®. Using this API, you can 

access these database systems using JDBC, SQLJ or pureQuery. SQLJ 

provides support for embedded static SQL in Java applications. 

Note: The IBM Data Server Driver is introduced with Client SDK beginning 

with Client SDK 3.50.XC7. At this writing, the Client SDK distributed with 

Informix database server is one (1) version less than the server version. As 

an example, Client SDK 3.50.XC6 is the version distributed with Server 

edition 11.50.XC7. 


The IBM Data Server Driver for JDBC and SQLJ is a single driver that 

includes JDBC Type 2 and JDBC Type 4 behavior. For connections to IBM 

Informix databases, only Type 4 behavior is supported. IBM Data Server 

Driver for JDBC and SQLJ Type 4 driver behavior is also referred to as IBM 

Data Server Driver for JDBC and SQLJ type 4 connectivity. For more 

information about these APIs, see the Java discussions at: 

http://publib.boulder.ibm.com/infocenter/db2luw/v9r5/index.jsp?topic=/com.i 

bm.db2.luw.apdv.java.doc/doc/rjvjdb2o.html 

► IBM Informix JDBC Driver 

IBM Informix JDBC Driver is a native-protocol, pure- Java driver (JDBC type 

4). Thus, when you use IBM Informix JDBC Driver in a Java program that 

uses the JDBC API to connect to an IBM Informix database, your session 

connects directly to the database or database server, without a middle tier. 

When deciding which JDBC interface to use, it is important to understand the 

differences between these two APIs. If you need to work with extended data 

types and features that are unique to IBM Informix databases, use IBM Informix 

JDBC Driver. 

To support DataSource objects, connection pooling, and distributed transactions, 

IBM Informix JDBC Driver provides classes that implement interfaces and 

classes described in the JDBC 3.0 API from Sun Microsystems. 

Informix classes implementing Java interfaces 

Table 1-2 lists the Java interfaces and classes and the Informix classes that 

implement them. 

Table 1-2 Java interfaces and classes 

JDBC interface class Informix class 

java.io.Serializable com.informix.jdbcx.IfxCoreDataSource 

java.sql.Connection com.informix.jdbc.IfmxConnection 

javax.sql.ConnectionEventListener com.informix.jdbcx.IfxConnectionEvent- 

Listener 

javax.sql.ConnectionPoolDataSource com.informix.jdbcx.IfxConnectionPoolData- 

Source 

javax.sql.DataSource com.informix.jdbcx.IfxDataSource 

javax.sql.PooledConnection com.informix.jdbcx.IfxPooledConnection 

javax.sql.XADataSource com.informix.jdbcx.IfxXADataSource 

java.sql.ParameterMetaData com.informix.jdbc.IfxParameterMetaData 


IBM Informix JDBC Driver, Version 3.0, and later implements the updateXXX() 

methods defined in the ResultSet interface by the JDBC 3.0 specification. These 

methods, such as updateClob, are further defined in the J2SDK 1.4.x API (and 

later versions) and require that the ResultSet object can be updated. The 

updateXXX methods allow rows to be updated using Java variables and objects 

and extend to include additional JDBC types. These methods update JDBC 

types implemented with locators, not the data that is designated by the locators. 

Informix classes Java specification 

To support the Informix implementation of SQL statements and data types, IBM 

Informix JDBC Driver provides classes that extend the JDBC 3.0 API. For 

information about the Java classes and the Informix classes that application 

programs can use to extend them, see IBM Informix JDBC Driver Programmer's 

Guide, v3.50, SC23-9421. 

Because IBM Informix has extended functionality, extra data types, and smart 

large objects, several Informix classes provide support for functionality that is not 

present in the JDBC 3.0 specification. Table 1-3 lists these classes. 

Table 1-3 Informix classes beyond the Java Specification 

JDBC interface or class Informix class Provides support for 

java.lang.object UDTManager Deploying opaque data types in the 

database server 

java.lang.object UDTMetaData Deploying opaque data types in the 


java.lang.object UDRManager Deploying user-defined routines in 

the database server 

java.lang.object UDRMetaData Deploying user-defined routines in 

the database server 

In releases prior to JDK Version 1.4, the UDTManager and UDRManager helper 

classes included in ifxtools.jar were not accessible from a packaged class. As 

of IBM Informix JDBC Driver 2.21.JC3, all these classes are in the udtudrmgr 

package. For backwards compatibility, unpackaged versions of these classes are 

also included. To access a packaged class, use the following import statements 

in your program: 

► Import udtudrmgr.UDTManager; 

► Import udtudrmgr.UDRManager; 


OLEDB 

Microsoft OLE DB is a specification for a set of data access interfaces that are 

designed to enable a variety of data stores to work together seamlessly. OLE DB 

includes the following components: 

► Data providers 

► Data consumers 

► Service components 

Each data provider makes data available to consumers in a tabular form through 

virtual tables. Data consumers use the OLE DB interfaces to access data. You 

can use the IBM Informix OLE DB Provider to enable client applications, such as 

ActiveX Data Object (ADO) applications and web pages, to access data on an 

Informix server. 

You can find detailed information about the characteristics of the IBM Informix 

OLE DB Provider in IBM Informix OLE DB Provider Programmer's Guide, 

Version 3.50, SC23-9424. The IBM OLEDB provider works with any IBM Informix 

Server version greater than or equal to 7.3 (7.3, 8.x, 9.x,10.x or 11.x). For 

information about OLE DB architecture and programming, go to the Microsoft 

website and search for “Introduction to OLE DB” topic: 

http://www.microsoft.com 

ESQL/C 

Informix ESQL/C is an API that enables you to embed SQL statements directly 

into a C program by means of the Informix ESQL/C preprocessor, esql. The 

preprocessor converts each SQL statement and IBM Informix-specific code to 

C-language source code and then invokes the C compiler to compile it. 

Informix ESQL/C includes the following components: 

► The Informix ESQL/C libraries of C functions, which provide access to the 

database server, and all the Informix data types 

► The Informix ESQL/C header files, which define the data structures, 

constants, and macros useful to an Informix ESQL/C program 

► The esql command, which processes the Informix ESQL/C source code to 

create a C source file that it passes to the C compiler 

► The finderr utility on the UNIX system and the Informix Error Messages 

Windows-based utility that provides information about IBM Informix specific 

error messages 

► GLS locale and code set conversion files for locale specific information 


1.2.3 4GL 

1.2.4 Ruby on Rails 

IBM Informix 4GL is a fourth-generation application development and production 

environment that provides power and flexibility without the need for 

third-generation languages such as C. The following package options are 

available for all UNIX and Linux operating systems: 

► Informix 4GL Rapid Development System and Informix 4GL Interactive 

Debugger provide a pseudo-compiled development environment for 

applications. 

► Informix 4GL C Compiler provides the components needed to develop and 

compile a high-performance application for a production environment. 

IBM Informix supports database access for client applications written in the 

popular and dynamic open source programming language called Ruby. To 

accomplish this, the developer must use a Ruby Driver and a Rails Adapter for 

the standard Ruby framework Rails. IBM Informix offers the following methods for 

using Ruby and Ruby on Rails: 

► The Ruby driver and Rails Adapter for IBM Data Servers is supported on 

Informix, Version 11.10 or later, using the DRDA protocol. This option requires 

the IBM Data Server Driver for ODBC and the call level interface (CLI) which 

are available as part of the Informix Client SDK. 

► Ruby/Informix and Rails Informix_adapter are specific for Informix database 

server and work with Informix database connections. Support all versions of 

the IBM Informix database servers and require the Client SDK libraries for the 

communication with the database server. 

You can download the both packages from the Rubyforge website at: 

http://rubyforge.org/projects/ruby-informix/ 

1.2.5 Informix DataBlade Developers Kit 

The IBM Informix DataBlade Developers Kit (DBDK) is an aid for developing 

DataBlade modules. The kit runs on Microsoft Windows and generates much of 

the code you need for a DataBlade. DataBlades can be developed without a 

DBDK on operating systems other than Windows; however, it is noteworthy that 

the procedures for setting up the development environment on a UNIX system 

are complex without help from DBDK. 


The DataBlade Developers Kit provides several graphical user interfaces for 

creating and working with Informix DataBlade modules.: 

► BladeSmith: A tool for organizing a DataBlade module development project. 

You can use BladeSmith to create a project and define the objects, such as 

data types and routines, that belong to the DataBlade module. BladeSmith 

generates source files, header files, make files, functional test files, SQL 

scripts, messages files, and packaging files. 

► DBDK Visual C++ Add-In and IfxQuery: Tools for debugging a DataBlade 

module using Microsoft Visual C++ on Windows. The add-in automates many 

of the debugging tasks and calls the IfxQuery tool to run unit tests for 

DataBlade module routines. 

► BladePack: A tool for creating a DataBlade module package. BladePack can 

create a simple directory tree containing files to be installed or an installation 

that includes an interactive user interface. 

► BladeManager: A command line tool on UNIX (or Windows) that comes with 

the Informix Server. It is a utility that is needed for registering and 

unregistering DataBlade modules in Informix databases. 

1.2.6 Informix Spatial DataBlade 

Many of the IBM Informix database servers support DataBlades. Of these 

DataBlades, a couple of blades are fairly popular because of their usefulness and 

flexibility. We introduce one of these blades here to open your interest into an 

area that you might not have considered. Location based data is one of several 

features and benefits that can be found in the IBM Informix Spatial DataBlade. 

The Spatial DataBlade can transform both traditional and location-based data 

into essential information through the following functions: 

► Expands IBM Informix Server to provide SQL-based spatial data types and 

functions that can be used directly through standard SQL queries or with 

client-side Geographic Information Systems (GIS) software. 

► Delivers innovative spatial technology through a convenient no-charge 

download. 

► Generates vital business intelligence for a competitive edge. 

► Maximizes spatial data capabilities to enable critical business decisions. 

► Works in an enterprise replication environment which includes spatial data 

types. 

► Enables organizations to manage complex geospatial information alongside 

traditional data, without sacrificing the efficiency of the relational database 

model. 


1.2.7 PHP on Informix 

► Includes R-tree indexing. 

R-tree is built into the database kernel and works directly with extended data 

types to enable proper geospatial data management. Unlike standard indices, 

the R-tree does not divide space into a full coverage of non- overlapping, 

adjacent cells. Instead, it uses data partitioning, where each object is 

automatically represented by a bounding box that is entirely determined by its 

own shape. These bounding boxes might overlap and do not need to cover 

the entire space. As a result there is no need to know the spatial extent of the 

data in advance. 

PHP, the powerful and popular server-side scripting language for creating web 

content, has become an important platform for Informix development. The 

Informix OpenAdmin Tool (OAT), which provides the ability to administer multiple 

Informix instances from a single location, is written entirely in the PHP language. 

Informix supports database access for client applications written in the PHP 

programming language by using a PDO (PHP Data Object) extension that 

functions as a database extraction layer. The primary PHP driver available for 

Informix is called PDO_IBM, and is supported on Informix Version 11.10, and 

following. The other available PHP driver is PDO_INFORMIX. It is the older of 

these two, and is the driver used for the Informix OAT. You can find the drivers for 

PHP on the PECL for PHP website at: 

http://pecl.php.net/package/PDO_IBM 

1.3 Informix overview 

This section provides a description of the database architecture from a developer 

perspective. There are entire manuals to describe server side functions and 

administration. In this section, we limit our overview to things that the developer 

should consider. For more information about the details of the IBM Informix 

Server engine, consult the IBM Informix Administrators Guide, which is available 

at: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/index.jsp?topic=/com.ibm. 

adref.doc/adref.htm 


1.3.1 Architecture overview 

An understanding of the Informix database server architecture is beneficial for 

application development. 

Client/server architecture 

IBM Informix servers are based on a multi-threaded client/server architecture. 

Regardless of the edition that you use, the server can support a large number of 

client connections while users are accessing data. A quick overview provides 

insights into what aspects influence development and what aspects might need 

DBA attention. 

The IBM Informix Server edition environments consist of several parts that are 

usually not directly visible to the developer. These parts include shared memory, 

disk storage, and virtual processors (VPs). The virtual processors are divided 

into VP classes to manage specific tasks, such as SQL query processing (CPU), 

physical and logical log processes (PIO and LIO), network connection processes 

(NET), engine administration (ADM), miscellaneous (MSC), and disk I/O (AIO 

and KAIO) processes. On UNIX and Apple Macintosh systems, VPs are visible 

as virtual processes. On Windows environments, the VPs are seen as 

threads.The program execution process is visible as oninit. Virtual processes 

communicate by way of shared memory structures known as mutexes (mutually 

exclusive). Because shared memory is also used to move database data in 

buffers, it helps to know that some memory buffers are reserved for engine 

processing and some buffers allocated (and managed dynamically) for data 

processing. 

Network protocols and other connection types 

Users can connect to IBM Informix Server using a network connection, shared 

memory, pipes, DRDA, or multiplexed connections. Shared memory and pipe 

connections are only available on the same system as the server instance. 

Network connections are the most popular, because they can connect different 

systems and will use either a TCP/IP or a socket connection, depending on the 

operating system. Regardless of the method that you choose, it is important to 

minimize the overhead costs associated with opening and closing connections. 

Keep sessions open only as long as it is prudent, and re-use connections when 

possible. 

Authentication and user connections 

By default, authentication is determined for users connecting to a database by 

the existence of a user name in the operating system environment. Other 

authentication methods include lightweight directory access protocol (LDAP), or 

single sign-on (SSO) through Kerberos. 


If you need a secured authentication method, IBM Informix Server also has two 

secured connection methods by way of the encrypted Communication Support 

Module (CSM) and single password CSM. You can use one or the other, but not 

both at the same time. Neither the encrypted CSM not the single password CSM 

method work over multiplexed connections. Enterprise Replication (ER) and high 

availability (HA) replication support encryption but not with CSM. Secure Sockets 

Layer (SSL) communications are an alternative to Informix-specific encryption 

CSMs. SSL encrypts data end-to-end and secures TCP/IP and Distributed 

Relational Database Architecture (DRDA) connections between two points 

over a network. For setup information, see the developerWorks® article Protect 

your data with Secure Sockets Layer support in Informix Dynamic Server, Part 1: 

Setting up SSL support in IDS, which is available at: 

http://www.ibm.com/developerworks/data/library/techarticle/dm-0912securesockets1 

/index.html 

Programming and user process considerations 

Any SQL or stored procedure call is parsed and optimized when the engine first 

receives the statement. Parsing and optimization methods require a little extra 

running time. If you can minimize this time, you can speed up query execution. 

The following factors can speed up execution time: 

► If you cannot optimize the query syntax in advance, have the DBA set the 

OPTCOMPIND parameter in the onconfig file to 2 to use distribution data 

(determined by Update statistics usage). 

► If you can optimize all of your query syntax expressions in advance, you might 

want your DBA to consider using OPTCOMPIND 1 or 2. 

► If the same statement is executed multiple times, it is placed in a procedure or 

dictionary cache. Cache statements run faster. 

► If the statement is a prepared statement, the statement can be shared by 

multiple users and does not need reparsing or optimizing. 

► When a statement execution thread is ready to run, it is scheduled to run on a 

CPU VP. On a system with multiple processors where each CPU VP maps to 

a physical processor, multiple statements can run concurrently on multiple 

CPU VPs. Take advantage of multiple CPUs whenever possible by means of 

concurrent queries, parallel subqueries, and the degree of parallelism. 

► When a statement runs on the CPU VP, it is given a brief block of time to run. 

At the end of the time unit, it is placed into a VP wait cycle, and the next 

statement thread gets a time block on the VP queue. This use of a wait cycle 

gives all executing processes an opportunity to make progress, regardless of 

the number of processes that are running. 


Physical and logical logging 

As each of the various CPU processes are running, the database engine keeps 

track of a number of operations. When data is retrieved from disk, the data image 

is placed in a physical log buffer. Change process information is placed in the 

logical log. When image data is affected by SQL processing, the physical image 

is modified periodically and written back to disk. 

During this process the physical log image and logical log information are also 

written into log records. Depending on the commit protocols and isolation levels, 

this information is available to the DBA through recovery operations in the event 

that the information is needed. The DBA can also use automatic recovery 

features that are built in to the engine can if the engine abruptly goes offline due 

to a power failure or crash. 

Commit protocols 

If transactions are made against a database that uses unbuffered logging, the 

records in the logical-log buffer are guaranteed to be written to disk during 

commit processing. When control returns to the application after the COMMIT 

statement (and before the PREPARE statement for distributed transactions), the 

logical-log records are on the disk. The database server flushes the records as 

soon as any transaction in the buffer is committed (that is, a commit record is 

written to the logical-log buffer). 

If transactions are made against a database that uses buffered logging, the 

records are held (buffered) in the logical-log buffer for as long as possible. They 

are not flushed from the logical-log buffer in shared memory to the logical log on 

disk until one of the following situations occurs: 

► The buffer is full. 

► A commit on a database with unbuffered logging flushes the buffer. 

► A checkpoint occurs. 

► The connection is closed. 

If you use buffered logging and a failure occurs, you cannot expect the database 

server to recover the transactions that were in the logical-log buffer when the 

failure occurred. Thus, you might lose some committed transactions. In return for 

this risk of using buffered logging, performance during alterations improves 

slightly. 


Consider using buffered logging only if the following situations: 

► If the database is updated frequently (speed of updating is important). 

► If the application that is performing the transaction can continue as it is and if 

you decide that the price (in time and effort) of returning the database to a 

consistent state by either removing the effects or reapplying the transaction is 

too high or you can re-create the updates in the event of failure. 

If a transaction failure does occur, you can simply choose to leave the 

database in its inconsistent state if the transaction does not significantly affect 

database data. 

As you consider whether to use a buffered or unbuffered logging method, 

remember that no automatic process or utility can perform a rollback of a 

committed transaction or can commit part of a transaction that has been rolled 

back. Without detailed knowledge of the application, messages are not enough 

to determine what has happened. Based on your knowledge of your application 

and your system, you might need to help the DBA determine when to roll back or 

to follow though on interrupted transactions. For more information about this 

topic, see the Guide to SQL: Tutorial section on interrupted modifications, which 

is available at: 


sqlt.doc/ids_sqt_277.htm 

1.3.2 Informix developer environment 

The environment references that you need have some variations, depending on 

whether you use the IBM common client API or the native Client SDK and which 

operating system you use. The environment settings must include identifying the 

following references to the components: 

► Setting the INFORMIXDIR environment variable to the installation directory of 

the software installation location. 

► Setting up Informix Server information (INFORMIXSERVER). 

► Adding the $INFORMIXDIR/bin to the PATH environment variable. 

On Windows, you have to set only the Informix database server information with 

the setnet32.exe utility. On UNIX-type platforms, you might want to set the 

environment variables so that they are set in your user profile at login or use a 

setup script. You also need to reference the sqlhosts file to identify Informix 

Server information. In the chapters that follow, we explain how to install the 

server and provide specific details for the relevant API environment details. 


Before you select an API or library, be aware that some operating systems are 

not available for some of the tools and that server functionality might not be 

accessible with some of the APIs. Consider the following information when 

making an API selection: 

► Client SDK 

– Optimized for IBM Informix database servers. 

– Works with PHP. 

– Directly interfaces with Informix Server; no middle tier required. 

– Supports all the Informix data types, extended data types, and smart 

BLOBs. 

► IBM Data Server Client 

– Optimized for compatibility and easy development with Informix and DB2 

IBM database servers. 

– Works with PHP and Ruby. 

– No available interface for Apple Mac systems. 

– Includes support for C and Fortran development. 

– No DataBlade API. 

1.3.3 Informix capabilities 

IBM Informix database servers provide a broad spectrum of features that allow 

resilience in response to fast changing systems and applications in a modern 

business environment. If you are aware of what the product can already do 

before you begin to develop, it aids and enables you to support applications and 

easily grow to meet new demands. 

This section provides a brief overview of the capabilities of Informix. 

Resilient 

High availability and fast recovery are standard aspects of an on-demand 

environment. Informix database server engines have a variety of ways to 

configure the instance, so there is little chance of the engine being unavailable at 

critical points in time. 

Reliable 

In addition to availability, there is a need for continuity. Informix has options to 

protect a server environment, such as backup servers, full independent copies of 

the processing environment for failover, and workload balancing at alternate 

locations around the world. 


Available 

There is an Informix solution to fit any situation that requires availability: 

► Continuous availability feature 

► High availability replication with allowance for multiple secondary servers 

Secure 

Informix supports open, industry-standard security mechanisms such as roles, 

password-based authentication, and RDBMS schema authorizations. These 

open standards ensure flexibility and security with easy validation and 

verification. Column-level encryption and Pluggable Authentication Modules 

(PAM) are also available. The Advanced Access Control Feature offers cell-, 

column-, and row-level label-based access control (LBAC). Thus, access to data 

can be controlled down to the individual cell level. 

Adaptable 

Informix is adaptable from the server side and from the client side. The engine 

component can be stripped down, embedded, and run with little user 

intervention. Using the developer tools that we discuss in this book, a developer 

can provide customized deployment by way of client applications and server-side 

processes, such as stored procedures, multiple triggers on tables and views, 

user-defined functions, and DataBlades 

Fast 

Informix is known for fast OLTP performance. Application performance is helped 

by capabilities such as committed isolation level and non-blocking checkpoints, 

which provide maximum concurrency. Direct I/O calls to file systems can result in 

performance similar to raw device I/O. SQL performance can be improved 

through techniques or configuration options that redirect or focus the engine’s 

optimizer decisions by way of optimizer directives in the SQL or by way of 

automated update statistics collection that inform the method used for running 

the query. When the DBA and the developer both focus on performance, it 

enables things to run more smoothly and reduces infrastructure costs. 

Flexible 

There are a number of APIs that are available, both as specific programming 

language supplements and as interfaces that extend the architecture of the 

server instance. In Informix 11 and following, the Web Feature Service API 

allows developers to use location-based services or location-enabled IT services. 

It is implemented in the Open GeoSpatial Consortium Web Feature Service 

(OGC WFS) API. This API also interacts with location-based data provided by 

the IBM Informix Spatial and Geodetic DataBlade modules. There is a significant 

amount of extensibility when using DataBlade technology. 


Hidden, behind-the- scenes tasking 

Business systems and applications need to work with minimum invasions into the 

operations of a business environment. From the server side, applications can run 

in an automated mode and perform self-maintenance. From an application 

perspective, database administrative tasks can be controlled and run from inside 

an application. The SQL Administration API allows you to do tasks such as space 

management, monitoring and manipulating memory, running scheduled tasks, 

and monitoring user sessions without developer intervention after they are setup 

and running. 

Customizable install footprint 

The installation of Informix can be automated, and the installation footprint can 

be customized using the Deployment Wizard so that you can limit the installation 

to only the data server functionality that you need and can reduce the size and 

costs of a solution for your software deployment. 

Affordable, reduced complexity 

When IBM or the developer adds features, the first impression is that the 

application will be more complex. With the features described up to this point, it is 

a surprise to discover that administration can actually be reduced by means of an 

application or one of the APIs and GUIs that we explain in this book. 


Chapter 2. Setting up an Informix 

development environment 

2 

This chapter describes how to set up an environment for Informix application 

development, including the installation and configuration of Informix Server and 

Informix Client. We focus our discussion on Informix Client products selection, 

installation, and configuration. Reading this chapter can help you understand 

how to complete the following tasks: 

► Decide which Informix Client product is suitable for your application. 

► Install and configure all Informix Client products that can connect to Informix. 

► Know any special consideration for each Informix Client in terms of 

connectivity. 

Note: In this chapter, we use the terms Informix database server, Informix 

Server, and Informix interchangeably. In addition, we also use the terms 

Client products, Client, and Informix Client interchangeably. 


2.1 Server setup 

In this section, we describe the various methods of installing Informix Server. We 

discuss how you can plan for the installation depending upon your specific 

requirement. We focus the discussion on the configuration that is required at the 

database server side to enable Informix Client connectivity. 

2.1.1 Planning for the installation 

In general, an application developer is not involved in the Informix Server product 

planning and installation. However, you need to communicate the application 

requirements to the DBA, who plans, installs, and configures the Informix 

database server for you. For example, the DBA needs to know if you need a 

smart blob space or a reduced footprint of the server or DataBlades. The 

Informix installer provides options to install only a small footprint of the server 

where you can add or remove the features as needed. For more information 

about DataBlades, see 10.3, “DataBlades and bladelets” on page 352. 

2.1.2 Installing Informix Server 

IBM provides the Informix Server editions, described in 1.1, “Server options” on 

page 2, in .zip, .tar, or .dmg format, depending on the platform on which 

Informix Server is installed. You can install Informix Server using several 

methods. The common installation methods include using the console, a GUI, or 

silent mode. 

Because we focus on Informix Client products for application development in this 

book, we describe only the silent mode of Informix Server installation on a UNIX 

platform. For other methods and platforms, refer to the individual installation PDF 

file that comes with the product. 

To perform a silent installation on UNIX, use the following steps: 

1. Extract the compressed .tar file into any directory using the following 

command: 

tar -xvpf IIF.11.50.tar 


2. Create the installation .ini file that specifies the installation options. You can 

use the sample installation .ini file, server.ini, as a template. The 

server.ini file is located in the directory that is used to extract the server 

media package. Edit the following information in the server.ini file, and save 

the file with a new name, for example myserver.ini: 

– Change -P installLocation="/opt/IBM/informix" to the location of 

directory where you want to install the product. 

– Change -G licenseAccepted= option to true to accept the software 

license. Otherwise, the installation process stops: 

3. Start the silent installation with the following command: 

./ids_install -silent -options myserver.ini 

Performing these steps installs Informix Server in your specified directory along 

with a demonstration instance by the name demo_on. 

For more information about Informix installation and creating new instances, refer 

to the installation guide PDF that comes with the media file. 

2.1.3 Configuring Informix Server 

The connectivity information allows a client application to connect to any IBM 

Informix database server in the network. The connectivity data for a particular 

database server includes the following connectivity data and information is 

required: 

► The host name of the computer or node on which the database server runs 

► The type of connection that an application can use to connect to the server 

► The service name or port number used by the database server 

► The database instance (also called the database server name) 

Even if the client application and the database server are on the same computer 

or node, you might need to specify connectivity information for your client 

application. 

Connectivity on UNIX 

On UNIX, the sqlhosts file contains the connectivity information. By default, this 

file resides in the $INFORMIXDIR/etc directory. You can use the 

INFORMIXSQLHOSTS environment variable to specify an alternative location for 

the connectivity information. Edit this file according to the protocol that you are 

using or the port number to which your client application will connect. 

Chapter 2. Setting up an Informix development environment 27

A typical sqlhosts file contains the following fields: 

Server Protocol Hostname Service/Port Options 

Here is an example: 

demo_on onipcshm on_hostname on_servername k=0 

demo_se seipcpip se_hostname sqlexec 

Each line in the sqlhosts file defines the following information about an Informix 

database server: 

► Server 

Specifies the name of the IBM Informix database server. This value normally 

correspond to the value in the INFORMIXSERVER environment variable. 

► Protocol 

Specifies the protocol that is used for the communication with the database 

server. It must be the same protocol that the database server uses. 

► Hostname 

Specifies the system where the Informix database server is running. 

► Service/Port 

Specifies the TCP port or service name, which must be defined in the 

/etc/services file, that is used by the Informix database server to accept 

incoming connections. 

► Options 

Specifies additional options for the communication, such as buffer size or 

connection redirection rules. 

APIs such as ESQL/C or ODBC rely on the sqlhosts file to obtain the 

connection parameters for the database server. 

Example 2-1 shows how a ESQL/C application connects to an Informix database 

server. 

Example 2-1 UNIX connection example 

informix@kodiak:/work$ cat $INFORMIXDIR/etc/sqlhosts 

#server protocol hostname service/port 

demo_on onsoctcp kodiak demo_on_tcp 

informix@kodiak:/work$ grep demo_on_tcp /etc/services 

demo_on_tcp 9089/tcp # Service for demo_on IDS server 

informix@kodiak:/work$ cat connect.ec 

#include 

int main() 


{ 

EXEC SQL CONNECT TO 'stores_demo@demo_on'; 

printf("Connected\n"); 

} 

informix@kodiak:/work$ esql connect.ec -o connect 

informix@kodiak:/work$ ./connect 

Connected 

informix@kodiak:/work$ 

The definition for the demo_on Informix Server specifies the communication 

protocol that is used as onsoctcp. The system where the database server is 

running is kodiak, and the TCP port that the server uses is demo_on_tcp. The 

service name is defined as port 9089 in the /etc/services configuration file. 

The ESQL/C example connects to the server and opens the stores_demo 

database using the following instruction: 

EXEC SQL CONNECT TO 'stores_demo@demo_on'; 

For more information about the sqlhosts file, refer to the IBM Informix Dynamic 

Server (IDS) Information Center topic: 


admin.doc/ids_admin_0158.htm 

Connectivity on a Windows system 

You can set the connectivity on a Windows system using the setnet32.exe utility 

that resides in the $INFORMIXDIR/bin directory. This utility is bundled with IBM 

Informix Client Software Development Kit (Client SDK). Use this utility to create 

or change the server name, protocol, service name, and host name. You also can 

use the setnet32.exe utility to set any environment variable that Informix 

products use. 


Figure 2-1 shows the Server Information tab of the setnet32.exe utility on a 

Windows system. Here, you can specify the server name, host IP address, 

network protocol, and service name. 

Figure 2-1 The Setnet32 Server Information tab 

Note: If you specify the name of the service (for example sqlexec) rather than 

the port number, make sure the service name that you use is defined in the 

Windows system services file that is located in the 

C:\WINDOWS\system32\drivers\etc directory. 

Enabling DRDA support 

Since version 11.x, Informix supports the DRDA protocol. If you plan to use the 

Data Server driver packages to connect to an Informix database server, you must 

enable DRDA support as described in this section. 


Windows systems 

Use the setnet32 utility to configure an Informix instance to use DRDA protocol: 

1. Start the setnet32 utility from any command window. 

2. Go to Server Information tab (Figure 2-2). 

a. Select the required instance from the IBM Informix Server field. Our 

example is demo_my. 

b. Change the name of the Informix server, and specify a new name for the 

DRDA alias, for example demo_my_drda. 

c. The HostName field is pre-filled. If it is not, enter your host name or IP 

address. 

d. Change the Protocolname field from olsoctcp to drsoctcp to make it 

DRDA compliant. 

e. Change the Service Name field to specify the service name or port 

number that the DRDA alias will use. 

Figure 2-2 Configuring DRDA support 

3. Click Apply, and then click OK. 

After adding all the connection details for the DRDA alias, the configuration file 

for the Informix database server must be updated to link the new server definition 


with the existing Informix instance. In our example, we use demo_my for the 

Informix database server and demo_my_drda for the DRDA instance. 

You can use the DBSERVERALIASES parameter in the onconfig file to specify 

an alias for a database server, as shown in Example 2-2. 

Example 2-2 Using the DBSERVERALIASES parameter 

... 

DBSERVERNAME demo_my # Name of default Dynamic Server 

# DBSERVERNAME or DBSERVERALIASES that uses a 

# DBSERVERALIASES - The list of up to 32 alternative UDRs, 

DBSERVERALIASES demo_my_drda # List of alternate dbserver names 

# DBSERVERNAME or DBSERVERALIASES that uses ... 

... 

The database configuration file is located in etc directory of your Informix 

database server. You can use the ONCONFIG environment variable to specify 

the name of this file. The complete path using environment variables for the 

database configuration file is: 

► On a UNIX platform, $INFORMIXDIR\etc\$ONCONFIG 

► On a Windows platform, %INFORMIXDIR%\etc\%ONCONFIG% 

You must restart the Informix database engine for the changes to take effect. 

After you complete these steps, the instance is now ready to accept connections 

as a DRDA compliant server. 


On a Windows system, you can enable the DRDA support for the demonstration 

instance during the installation if you use the Custom installation option. 

Figure 2-3 shows the installation panel where you enable the DRDA support. 

Figure 2-3 Enable DRDA support for the default instance 

Linux and UNIX systems 

On Linux and UNIX systems, you can enable the DRDA support by editing the 

following Informix configuration files: 

► Edit the sqlhosts file specified in the $INFORMIXSQLHOSTS environment 

variable, and add the following line: 

drsoctcp 

where: 

– is the name for the DRDA alias 

– drsoctcp is the protocol used by the new alias 

– the name or IP address of the system that is running Informix 

Server 

– is the name of the TCP service or port number for 

the DRDA instance 


2.2 Client setup 

► Edit the Informix Server configuration file located in the etc directory of your 

Informix Server directory to include the new database definition as an alias for 

the existing Informix Server. 

You can use the environment variables to access this file, for example 

$INFORMIXDIR/etc/$ONCONFIG. This file is the file that contains a list of 

configuration parameters for Informix Server. Example 2-3 shows the 

configuration file that we used in our database server. 

Example 2-3 Linux onconfig file sample 

informix@irk:/usr3/11.50$ grep DBSERV $INFORMIXDIR/etc/$ONCONFIG 

# DBSERVERNAME - The name of the default database server 

# DBSERVERALIASES - The list of up to 32 alternative UDRs, 

# DBSERVERNAME or DBSERVERALIASES that uses a 

DBSERVERNAME demo_my 

DBSERVERALIASES demo_my_drda 

You must restart Informix Server for these changes to take effect. 

You can find additional information about the sqlhosts file at: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.admin.doc/i 

ds_admin_0158.htm 

Informix is a low-administration, easy-to-use, and embeddable database that 

supports various application development languages and technologies, such as 

Java, .NET, PHP, and Web Services. Informix can handle XML data easily and 

can be extended to handle new data sets using DataBlades. 

In this section, we describe how to install and configure Informix Client products 

to support the application development that you need. 

2.2.1 Informix Client options 

IBM offers the following Informix Client products that you can use to develop and 

use an IBM Informix database server: 

► IBM Informix Client Software Development Kit (Client SDK) includes several 

APIs that are designed for developing with an Informix database. 

► IBM Informix Connect is a runtime version of Client SDK. 


► IBM Informix JDBC Driver is Java driver that is optimized for Informix 

databases. 

► IBM Data Server Client includes the API tools that are needed for 

development with IBM databases such as DB2 and Informix, plus functionality 

for database administration and client/server configuration. 

► IBM Data Server Runtime Client is the runtime version of the IBM Data Server 

Client. 

► IBM Data Server Driver Package is a lightweight version of the IBM Data 

Server Runtime that includes only the interfaces and drivers. 

► IBM Data Server Driver for JDBC and SQLJ is a Java driver for IBM Data 

Servers. 

Client SDK and Informix Connect have distinct functions: 

► Client SDK contains a group of application-programming interfaces (APIs) 

that developers can use to write applications for Informix, plus other client 

components. Client SDK must be installed on computers that application 

programmers will use to write applications. 

► Informix Connect contains runtime libraries of the Client SDK APIs, plus other 

client components. Install Informix Connect on computers that users use to 

connect to Informix database servers. 

The same rule applies to IBM Data Server products. Do not use packages that 

are designed for development, such as IBM Data Server Client, to deploy an 

application. Some components, such as Informix JDBC Driver, do not have a 

specific runtime version, so you can use the same product in both cases. 

In addition to these products, you can use open source drivers, such as PHP or 

Ruby, to develop with an IBM Informix database. 


Figure 2-4 illustrates the options that are available to develop with an IBM 

Informix database. 

Figure 2-4 Available Informix Client products for application development 

2.2.2 Installing and setting up Client SDK 

IBM Informix Client Software Development Kit (Client SDK) is a collection of 

components for developing and running client applications that connect to the 

Informix database server. Client SDK bundles with the following components and 

utilities: 

► ESQL/C with XA support 

► IBM Informix Object Interface for C++ 

► IBM Informix OLE DB Provider (Windows only) 

► IBM Informix ODBC Driver with MTS support 

► IBM Informix .NET Provider (Windows only) 

► IBM Informix GLS 

► The Global Security Kit (GSKit) 

► Password Communication Support Modules (CSM) 

► Documentation Viewer 


► The finderr utility on UNIX systems and the Informix Error Messages utility 

on Windows systems 

► The iLogin utility (Windows only) 

Starting from version 3.50.xC5, the IBM Data Server Driver Package is also 

bundled with the Windows system version of Client SDK and Informix Connect. 

Client SDK provides access to all the Informix database servers. Table 2-1 lists 

the Informix database servers that supports Client SDK. 

Table 2-1 Supported database servers 

Database server Versions 

IBM Informix 7.x, 9.x,10.x and 11.50 

IBM Informix Extended Parallel Server 8.50 and higher 

IBM Informix Standard Engine 7.25 

IBM Informix Online 5.20 and higher 

Some components, such as Informix OLE DB Provider, do not allow a connection 

to an IBM Informix Standard Engine server. Refer to the component release 

notes for more information: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.relnotes.do 

c/relnotes_ClientSDK350xc7.html 

Completing the preliminary tasks 

Before you install Client SDK, perform the following preliminary tasks: 

1. Determine the following locations: 

– Media location: This directory is the directory where all the media files 

reside. 

– Installation location: This directory is the location where the installer 

places all the binaries and the configuration files. This directory is 

represented by the environment variable $INFORMIXDIR. If 

$INFORMIXDIR is set, the defined location is the default installation 

location. 

– Java location: The script that is used during the installation process 

requires the use of a Java virtual machine (JVM). A JVM is bundled 

together with Client SDK. However, if required, it is possible to specify a 

different JVM for the installation process. The minimum version is Sun 

JRE 1.4.2. 


2. Prepare the environment. 

You need to check if you have the informix user and the informix group on 

your computer. If you do not, create them. For additional information, refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.igul.do 

c/ids_in_005x.htm 

Installing the Client SDK 

Informix provides various methods for installing Client SDK. In this section, we 

demonstrate using the GUI to install in both UNIX and Windows environments. 

Installing Client SDK on UNIX using the GUI 

To install Client SDK in GUI mode: 

1. Start the installation GUI with the following command from the root user: 

./installclientsdk -gui 

Remember to set the DISPLAY environment variable to the window that you 

want to project the installation. Figure 2-5 shows the Welcome panel. 

Click Next. 

38 IBM Informix Developer’s Handbook 

Figure 2-5 Installation of Client SDK on UNIX Welcome panel 

2. On the license agreement panel, select I accept the terms and the license 

agreement and click Next.

3. Specify the directory where you want to install Informix Client (Figure 2-6). 

Enter the full path name. Click Next. 

Figure 2-6 Specify the installation directory 

4. Select Typical or Custom (Figure 2-7). A Custom installation allows you to 

select the features to install. Click Next. 

Figure 2-7 Select the type of installation 


5. If you selected a Custom installation, you next need to select the features that 

you want to install and click Next (Figure 2-8). If you want to install whatever 

the installer offers, select a Typical installation. 

Figure 2-8 Custom options to choose 


6. The installer presents the summary of available space and the components 

that you have chosen for installation, as shown in Figure 2-9. If needed, you 

can go back and change the installation selections. Click Next to start the 

installation. 

Figure 2-9 Installation summary 

7. Figure 2-10 shows that the installation is complete without any errors. 

Figure 2-10 Installation complete without any errors 


At this stage, the Client SDK installation is complete. If the Informix database 

server is located on a different system, you might need to set up the connection 

information and modify the sqlhosts file, using the details of your Informix 

Server. 

Installing Client SDK on a Windows system 

Installation on a Windows system for the Client SDK is similar to UNIX the 

installation except that the Windows system installation has the option to install 

IBM Data Server Driver Package. If you select the option to install these drivers, 

refer to “Installing the IBM Data Server Driver package” on page 44 for 

Installation details. 

Configuration utility 

On Windows systems, the Client SDK comes bundled with the setnet32.exe 

utility for configuring the Client SDK. The Client SDK has default values set and 

is ready to use unless you want to change the protocol, server information, or any 

environment variable under which the client application runs. 

The setnet32.exe utility sets environment variables and network parameters that 

IBM Informix products use at run time. The environment variables and 

connectivity parameters are stored in the Windows system registry and are valid 

for every Informix Client product that you install, except Informix JDBC Driver. 

The setnet32.exe utility has the following tabs: 

► The Environment tab allows you to set environment variables. 

► The Server Information tab allows you to set database server network 

information. 

► The Host Information tab allows you to set your host computer and login 

information. 

► The About Setnet32 tab provides information about the setnet32.exe utility. 

For more information about these tabs, refer to the Client SDK installation PDF 

file that comes with Client SDK. 

Special consideration for 32- and 64-bit products 

Beginning with version 3.50.FC4, you can install both 32-bit and 64-bit Client 

SDK on the same Windows system. 

Before installing the version 3.50.FC4 product, you must uninstall the existing 

version 3.50.FC3 or earlier Client SDK from your system. 


To uninstall your existing products, use one of the following methods: 

► Use the Add/Remove program. 

► Run the setup.exe program from the installed product media. When the 

Maintenance Menu displays, select Remove. 

You must install the new 32-bit and 64-bit products in separate directories. 

The 32-bit Client SDK installs in the following directory by default: 

C:\Program Files (x86)\IBM\Informix\Client-SDK 

The 64-bit Client SDK installs in the following directory by default: 

C:\Program Files\IBM\Informix\Client-SDK 

The 64-bit product installation adds a suffix to the Program group folder and the 

Add/Remove entry. This suffix provides an easy identification between the 32-bit 

(no suffix) and 64-bit (suffix) product installations. For more information, refer to 

the release notes. 

2.2.3 Setting up IBM Data Server drivers 

Several types of IBM Data Server Clients and Drivers are available. 

The following IBM Data Server Clients are available: 

► IBM Data Server Client, contains all the APIs and tools that are needed for 

development against DB2 and Informix databases, including tools for remote 

administration. 

► IBM Data Server Runtime Client, contains all the APIs but only the minimum 

number of utilities for setup and configure the development environment. 

► IBM Data Server Driver Package, contains only the APIs and drivers without 

any additional tools. 

The client products contain the APIs and drivers plus additional tools that are 

designed for remote database administration and configuration of the client 

environment. 

The following IBM Data Server Drivers are available: 

► IBM Data Server Driver for JDBC and SQLJ 

► IBM Data Server Driver for ODBC and CLI 

► IBM Data Server Driver for .NET 

► IBM Data Server open source drivers such as PHP or Ruby 


You can download some of these components and install them as separate 

products. 

Each IBM Data Server Client and driver provides a particular type of support: 

► For Java applications only, use IBM Data Server Driver for JDBC and SQLJ. 

► For applications using ODBC or CLI only, use IBM Data Server Driver for 

ODBC and CLI 

► For applications using ODBC, CLI, .NET, OLE DB, PHP, Ruby, JDBC, or 

SQLJ, use IBM Data Server Driver Package. 

► IBM Data Server Runtime Client and IBM Data Server Client includes all of 

above drivers and some functions of DB2. 

In this section, we discuss the installation and configuration of the following 

drivers for UNIX and Windows platforms: 


► IBM Data Server Driver for ODBC and CLI 

► IBM Data Server Driver Package 

For the installation and configuration of IBM Data Server Runtime Client and IBM 

Data Server Client, refer to: 

http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/index.jsp?topic=/com.ibm.s 

wg.im.dbclient.install.doc/doc/c0022615.html 

Installing the IBM Data Server Driver package 

The IBM Data Server Driver package is a lightweight solution and the 

recommended package for user code deployment. It provides robust runtime 

support for applications using ODBC, CLI, .NET, OLE DB, PHP, Ruby, JDBC, or 

SQLJ without the need of installing Data Server Runtime Client or Data Server 

Client. Here we discuss the installation of the drivers presented under the IBM 

Data Server Driver Package. 

Installing the driver package on UNIX and Linux 

You can download the IBM Data Server Driver Package and individual drivers 

such as IBM Data Server Driver for JDBC and SQLJ from the IBM Support and 

downloads website at: 

http://www.ibm.com/support/docview.wss?rs=4020&uid=swg21385217 

Extract IBM Data Server Drivers Package to an empty directory after you 

download it. 

If you want to install the complete IBM Data Server Driver Package, run the 

installIDSDriver command. This driver package includes database drivers for 


Java, ODBC/CLI, PHP, and Ruby on Rails, each of which is stored in its own 

subdirectory. The Java and ODBC/CLI drivers are compressed. 

If you want to install individual drivers that are contained in the driver package, 

follow these steps (first two steps are common for all drivers): 

1. Extract the Data Server Driver Package archive onto the target system. 

2. For the Java and ODBC/CLI drivers, extract the driver file into the chosen 

installation directory. 

3. Install the driver that you need: 

– Java 

This driver provides support for client applications written in Java using 

JDBC. The path and file name of the Java driver are 

Path: jdbc_sqlj_driver/platform 

File name: db2_db2driver_for_jdbc_sqlj.zip 

For additional information, refer to “Installing IBM Data Server Driver for 

JDBC and SQLJ” on page 51. 

– ODBC and CLI 

The open source drivers included in the IBM Data Server Driver Package, 

such as PHP or Ruby driver, require the use of the Data Server CLI driver 

for connection to the database engine. If you plan to use any of these 

drivers, you need to install the ODBC driver. 

Path: odbc_cli_driver/platform 

File name: ibm_data_server_driver_for_odbc_cli.tar.Z 

For additional information, refer to “Installing IBM Data Server Driver for 

ODBC and CLI” on page 52. 

– PHP 

The IBM_DB2 and PDO_IBM are the PHP extensions for IBM Data 

Servers including Informix. Installing the IBM_DB2 or PDO_IBM 

extensions enables any application in the PHP environment to interact with 

Informix database servers. The extensions included with the IBM Data 

Server Driver Package might be of a lower version as compared to the one 

available on the PHP repository. 

Download the latest extension from PHP repository page because it might 

contain important fixes and new features: 

For IBM_DB2 

http://pecl.php.net/package/ibm_db2 

For PDO_IBM 

http://pecl.php.net/package/pdo_ibm 



The PHP driver path and file names in the IBM Data Server Driver 

Packages are as follows: 

Path 

php_driver/platform/php32 or php_driver/platform/php64 

Files 

ibm_db2_n.n.n.so and pdo_ibm_n.n.n.so 

where n represents the version of the extension. 

Consider the following information before you install the PHP driver: 

Prerequisite: The PHP drivers require the ODBC/CLI driver that is also 

included in the IBM Data Server Driver Package to be installed. 

Installation instructions: The following online information explains how 

to install PECL extensions. 

Through the source code: 

http://www.php.net/manual/en/install.pecl.phpize.php 

Through the PECL command: 

http://www.php.net/manual/en/install.pecl.pear.php 

Installing the IBM_DB2 extension: 

http://www.php.net/manual/en/ibm-db2.installation.php 

Installing the PDO_IBM extension: 

http://www.php.net/pdo_ibm 

– Ruby on Rails 

The IBM_DB adapter and driver as a gem enables any application in the 

Ruby environment, including Rails, to interact with IBM data servers. The 

path, file name, and installation information for Ruby on Rails Driver is as 

follows: 

Path 

ruby_driver/platform 

File 

ibm_db-0.10.0.gem

Consider the following information before you install the Ruby on Rails 

Driver: 

Prerequisite: The Ruby on Rails Driver requires the ODBC/CLI driver 

that is also included in the IBM Data Server Driver Package to be 

installed. 

To install the Ruby on Rails Driver, from the location of the gem file, run 

the following command: 

gem install ibm_db-0.10.0.gem 

You are now ready to use any of these drivers on UNIX or Linux. 

Installing the driver package on Windows 

You can obtain the Data Server Driver Package for windows from the same site 

as the package for UNIX: 

http://www.ibm.com/support/fixcentral/ 

The file for Windows is an .exe file, which is the installation file for the driver 

package. 

To install the driver package: 

1. Start the installation by executing the .exe file. The welcome window opens, 

as shown in Figure 2-11. Click Next. 

Figure 2-11 Welcome panel for Data Server Driver Package 


2. On the Software License Agreement panel, accept the license agreement, 

and click Next. 

3. Specify the installation directory in the Custom Setup panel (Figure 2-12). You 

can change the installation directory to a location other then the default. Click 

Next. 

Figure 2-12 Change the installation directory 


4. The IBM data server driver copy name is used to identify a location where 

IBM Data Server Driver Package is installed on the computer. Enter the copy 

name for the location that you have chosen, the default is IBDBCL1 

(Figure 2-13). Click Next. 

Figure 2-13 Set the IBM data server driver copy name 


5. Verify the installation selections on the summary panel (Figure 2-14). If 

everything is correct, begin the installation by clicking Install. 

Figure 2-14 Summary of the installation 


6. When the installation completes, the complete panel opens as shown in 

Figure 2-15. Click Finish. The installation of Data Server Driver for Informix is 

complete. 

Figure 2-15 Installation complete 

Note: The Windows installer of the IBM Data Server Driver Package does not 

provide any option to install individual components. All the drivers and 

interfaces that are included in the package are installed by default. 

Installing IBM Data Server Driver for JDBC and SQLJ 

To install IBM Data Server Driver for JDBC and SQLJ: 

1. Obtain Java SDK. 

Before you install the IBM Data Server Driver for JDBC and SQLJ, you must 

have an SDK for Java installed on your computer: 

– For JDBC 3.0 functions, you need Java SDK 1.4.2 or later. 

– For JDBC 4.0 functions, you need Java SDK 6 or later. 

2. Download the .zip file for the latest version of the IBM Data Server Driver for 

JDBC and SQLJ at: 

http://www.ibm.com/software/data/support/data-server-clients/download.html 


3. Extract the IBM Data Server Driver for JDBC and SQLJ compressed file to the 

installation location. The compressed file contains the following files: 

– db2jcc.jar 

– db2jcc4.jar 

– sqlj.zip 

– sqlj4.zip 

4. Modify the CLASSPATH environment variable to include the appropriate files, 

You can set the CLASSPATH using the following command: 

java -classpath \.jar 

– For JDBC: 

Include the db2jcc.jar file in the CLASSPATH if you plan to use the 

version of the IBM Data Server Driver for JDBC and SQLJ that includes 

only JDBC 3.0 and earlier functions. 

Include the db2jcc4.jar file in the CLASSPATH if you plan to use the 

version of the IBM Data Server Driver for JDBC and SQLJ that includes 

JDBC 4.0 and earlier functions. 

– For SQLJ 

The steps are similar to the JDBC except that the files to be included in 

CLASSPATH are sqlj.zip and sqlj4.zip. 

For more information regarding configuration and customizing of the IBM Data 

Server Driver for JDBC and SQLJ, refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.jccids.doc/ 

ids_jcc_0008.htm 

Installing IBM Data Server Driver for ODBC and CLI 

The IBM Data Server Driver for ODBC and CLI solution is designed mainly for 

independent software vendor (ISV) deployments.To install the IBM Data Server 

Driver for ODBC and CLI: 

1. Depending on your operating system, download the compressed file that is 

available at: 

https://www14.software.ibm.com/webapp/iwm/web/preLogin.do?land=en_US&source 

=swg-informixfpd 

2. Extract the file to an installation directory of your choice. 


Important: Include either the db2jcc.jar or the db2jcc4.jar files in the 

CLASSPATH. Do not include both files.

3. On Mac OS X, set the DYLD_LIBRARY_PATH environment variable to the 

clidriver/lib directory path. 

For specific information about the setup and configuration of the ODBC, refer to 

3.2, “Setup and configuration” on page 58. 

2.2.4 Setting up Informix JDBC 

Informix JDBC is a platform independent, industry-standard driver that provides 

enhanced support for distributed transactions. It consists of a set of interfaces 

and classes written in the Java programming language which can run on AIX, 

HP-UX, Linux, Solaris, Windows, and all other platforms that support Java. It also 

supports extensibility with a user-defined type (UDT) routine manager that 

simplifies the creation and use of UDTs. 

JCC support is available through the IBM Data Server Driver package that has a 

driver to run Java application using JCC. 

This section describes how to install Informix JDBC Driver, which is bundled with 

the Informix database server. There is a separate JDBC directory with a .jar file 

inside when you extract the Informix database server from the installation media. 

Informix JDBC Driver, Version 3.50, strives to be compliant with the Sun 

Microsystems JDBC 3.0 specification. Nearly all the features that are required for 

the Sun Microsystems JDBC 3.0 specification have the specified behavior. For 

the Sun Microsystems JDBC 3.0 driver optional features, if the feature is 

supported by IBM Informix Version 11.50, then it is supported by Informix JDBC 

Driver, Version 3.50. 

Informix JDBC Driver is a native-protocol, pure-Java driver (Type 4). Thus, when 

you use Informix JDBC Driver in a Java program that uses the JDBC API to 

connect to an Informix database, your session connects directly to the database 

or database server without a middle tier 

Installing the JDBC driver 

The JDBC driver installation procedure is same for both Windows and UNIX 

platforms. 

To install the JDBC driver in console mode, use the following command: 

java -cp dir/setup.jar run -console 


For a silent installation on both Windows and UNIX, run the following command 

from a command prompt: 

java -cp /setup.jar run -silent -P 

product.installLocation= 

where: 

► is the location of the setup.jar file 

► is the directory where you want to install the JDBC driver 

The installation is complete when the command finishes executing. If you want to 

log information during the installation, specify the -log parameter. 

To install Informix JDBC Driver in GUI mode on Windows: 

1. Start the GUI mode installation with the following command: 

java -cp dir/setup.jar run 

The Welcome panel opens (Figure 2-16). Click Next. 


Figure 2-16 Starting panel for JDBC informix installation 

2. Accept the license agreement, and click Next.

3. Specify the installation directory or use the default location as shown in 

Figure 2-17, and click Next. 

Figure 2-17 Specify the installation directory 

4. Review the summary information that displays (Figure 2-18), and click Next 

complete the installation. 

Figure 2-18 Summary window 


Configuring the JDBC driver 

To use JDBC driver in an application, you must set the CLASSPATH environment 

variable to point to the driver files. The CLASSPATH environment variable tells 

the JVM and other applications where to find the Java class libraries that are 

used in a Java program-log parameter. 

UNIX 

Use one of the following methods to set the CLASSPATH environment variable 

on a UNIX system: 

► Add the full path name of the ifxjdbc.jar file to CLASSPATH: 


setenv CLASSPATH /jdbcdriv/lib/ifxjdbc.jar:$CLASSPATH 

► Extract the ifxjdbc.jar file, and add its directory to CLASSPATH: 

cd /jdbcdriv/lib 

jar xvf ifxjdbc.jar 

setenv CLASSPATH /jdbcdriv/lib:$CLASSPATH 

Windows system 

Use one of the following methods to set the CLASSPATH environment variable 

on a Windows system: 

► Add the full path name of the ifxjdbc.jar file to CLASSPATH: 

set CLASSPATH=c:\jdbcdriv\lib\ifxjdbc.jar;%CLASSPATH% 

► Extract the ifxjdbc.jar file, and add its directory to CLASSPATH: 

cd c:\jdbcdriv\lib 

jar xvf ifxjdbc.jar 

set CLASSPATH=c:\jdbcdriv\lib;%CLASSPATH% 

You are now ready to develop a Java application using JDBC.

Chapter 3. Working with the ODBC 

driver 

This chapter discusses the configuration and development of applications using 

Open Database Connectivity (ODBC) interfaces to access an Informix database 

server. 

This chapter includes the following topics: 

► ODBC and Informix 

► Setup and configuration 

► Developing an ODBC application 

3 


3.1 ODBC and Informix 

ODBC is a software API method based on the X/Open Call Level Interface to 

access data from a database management system. ODBC allows developers to 

write database applications without having to know a proprietary interface for a 

specific database. In an ODBC environment, the ODBC driver is the component 

that directly communicates with the database server. It receives calls from the 

application or the ODBC Driver Manager and converts those calls into messages 

that the database server can understand. 

The following ODBC drivers for Informix are available: 

► IBM Informix ODBC Driver 

► IBM Data Server Driver for ODBC and CLI (CLI Driver) 

3.2 Setup and configuration 

In this section, we discuss the setup and configuration parameters of the ODBC 

driver. 

3.2.1 IBM Informix ODBC Driver 

The Informix ODBC Driver is installed by default as part of Informix Client 

Software Development Kit (Client SDK). It is based on the Microsoft Open 

Database Connectivity (ODBC) Version 3.0 standard. 

Table 3-1 lists the Informix database server that support Informix ODBC. 

Table 3-1 Supported databases 

Database server Versions 

IBM Informix 10.0,11.10,11.50 


IBM Informix Standard Engine 7.25 


Windows system configuration 

On a Windows system, the ODBC drivers is registered automatically within the 

system during the Informix installation process. 


The following directory is the default installation directory: 

C:\Program Files\IBM\Informix\Client-SDK 

The INFORMIXDIR environment variable points to the directory where the 

product was installed. 

Note: If you install a 32-bit version of Client SDK on a Windows x64, the 

default directory is C:\Program Files (x86)\IBM\Informix\Client-SDK. 

The ODBC driver requires that additional libraries are loaded. These libraries are 

located in the %INFORMIXDIR%\bin directory. Make sure that this directory is part 

of your PATH variable. 

The name of the ODBC driver depends on the version: 

► IBM Informix ODBC Driver: For the Windows 32-bit driver, see Figure 3-1. 

Figure 3-1 Windows x86 ODBC driver administrator 

Chapter 3. Working with the ODBC driver 59

► IBM Informix ODBC Driver (64-bit): for the Windows 64-bit driver. See 

Figure 3-2. 


Figure 3-2 Windows x64 ODBC driver administrator 

To create an Informix ODBC Data Source (DSN), open the ODBC Administrator, 

choose a DSN type, and select the Informix ODBC driver, the DSN-configuration 

parameters are common to both drivers (32-bit and 64-bit). 

Note: The default ODBC Data Source Administrator on a Windows x64 

system is the 64-bit version. If you want to create a 32-bit ODBC DSN you 

must use the 32-bit version 

C:\WINDOWS\SysWOW64\odbcad32.exe

Figure 3-3 shows the Informix ODBC Connection tab. 

Figure 3-3 Connection parameters 

Table 3-2 lists the required DSN parameters. If you have already defined an 

Informix server using the setnet32.exe utility, which is a component of Client 

SDK, most of these values are updated automatically when selecting an Informix 

server from the drop-down box. 

Table 3-2 Required DSN values 

Parameter Description 

Data source name Name of the DSN 

Server name Name of the Informix database server 

Host name Name or IP address of the computer where the database server 

runs 

Service Name or value of the tcp service used by the database server 

Protocol Communication Protocol used by the database server 

Database Name of the database to which the DSN connects by default 


You can set optional configuration parameters in the Environment and Advanced 

tabs (Figure 3-4). 

Figure 3-4 Environment parameters 

Table 3-3 describe the parameters for the Environment tab. 

Table 3-3 Environment parameters 


Client Locale Locale for the client machine 

Database Locale Locale used when the database was created 

Use Server Database Locale Using this option the Database Locale is automatically 

retrieved from the database 

Translation Library Code set conversion library 

Translation Option Options for a third-party conversion library 

Cursor Behavior Close or preserve a cursor when a transaction is 

resolved 

VMB Character How to report the length for Varying Multi byte 

characters 

Fetch Buffer Size Size of the communication data package 

Isolation Level Default Isolation Level for the connection 


Note: The code set value for the Client Locale parameter is determined by the 

code set used in the application, which in most cases is the same as the 

operating system. The default code set on a Windows system is CP1252. 

The default code set for an Informix database is en_us.8859-1 (ISO 8859-1). 

Some versions of the IBM Informix database server (for example, Version 9.40 

and Version 10.00) allow a connection from a client with a mismatched 

DB_LOCALE value. This option is no longer available. A client application 

must set the Database Locale parameter (DB_LOCALE) to the same value as 

the locale of the database (locale used at creation time). 

The typical syntax for an Informix locale is language_territory@codeset. 

Figure 3-5 shows the Advanced tab configuration parameters. 

Figure 3-5 Advanced parameters 

Table 3-4 describes the parameters for the Advanced tab. 

Table 3-4 Advanced parameters 


Auto Commit Optimization Optimize client-server communication deferring 

the commit work after all the cursors are close. 

Open-Fetch-Close Optimization Optimize client-server communication 

automatically closing the cursor after all the 

rows have been retrieved. 



Insert Cursors Buffers all the rows send by an insert cursor 

and uses only one package to send the data to 

the server. 

Scrollable Cursors Enable scrollable cursors. 

Report KeySet Cursors Report support for KeySet-driver cursors. 

Report Standard ODBC Types Only Report standard ODBC types Only. Extended 

types are mapped to standard ODBC types. 

Describe Decimal Floating Point as 

SQL_REAL / SQL_DOUBLE 


Decimal columns without a scale are reported 

as SQL_REAL or SQL_DOUBLE. 

Do Not Use Lvarchar Do not report Lvarchar columns when using 

SQL_VARCHAR. 

Report Char columns as Wide Char 

columns 

length in Chars for 

SQLGetDiagRecW 

Char columns described by SQLDescribeCol 

are reported as Wide char columns 

(SQLWCHAR) 

Returns the number of characters rather than 

the number of bytes.

For more information about each one of these parameters, place the cursor over 

a parameter, and press F1 (Figure 3-6). 

Figure 3-6 ODBC DSN Help 

UNIX configuration 

On UNIX platforms, the default installation directory for Client SDK is the 

/opt/IBM/informix directory. 

The INFORMIXDIR environment variable should point to the directory where the 

product was installed. 

On UNIX platforms, an ODBC driver manager is not normally supplied as part of 

the operating system. Client SDK does not include an ODBC driver manager 

library, however, the Client SDK does have a Driver Manager Replacement 

(DMR) library which provides most of the features of an ODBC driver manager. 

If the application does not use an ODBC driver manager, such as unixODBC or 

Data Direct Driver Manager, the application must be linked directly to the Informix 

ODBC libraries. The ODBC libraries are located in the $INFORMIXDIR/lib/cli 

directory. 


Table 3-5 shows the ODBC libraries that are included with Client SDK. 

Table 3-5 UNIX ODBC libraries 

Library Description 

libifcli.a or libcli.a Static version for single (nonthreaded) 

libifcli.so or iclis09b.so Shared version for single (nonthreaded) 

libthcli.a Static version for multithreaded library 

libthcli.so or iclit09b.so Shared version for multithreaded library 

libifdrm.so or idmrs09a.so Shared library for DMR (thread safe) 

The shared-library path environment variable specifies the library search path. 

This variable should contains at least $INFORMIX/lib, $INFORMIXDIR/lib/esql, 

and $INFORMIXDIR/lib/cli for the ODBC driver to work. 

There are three configuration files for the ODBC driver: 

► sqlhosts 

► odbc.ini 

► odbcinst.ini 

Note: The information in the sqlhosts file is also used by all the other Client 

SDK components and by the Informix database server. Be aware that any 

changes in this file can have an impact in other clients and servers. 

On a Windows system, instead of using a text file, this information is stored in 

the registry through the setnet32.exe utility. 

The sqlhosts file 

This text file contains most of the information that is required to connect to an 

IBM Informix database server. 

The default location for this file is the $INFORMIXDIR/etc/sqlhosts directory. You 

can use the INFORMIXSQLHOSTS environment variable to point to a different 

location. 

Example 3-1 shows a simple sqlhosts file. 

Example 3-1 The sqlhosts file 


on_demo onsoctcp kodiak 9088 


For more information about the sqlhosts file, refer to the Client/Server 

Communications manual at: 



The odbcinst.ini file 

This file contains a list of installed ODBC drivers on the UNIX system and 

specific attributes for each driver, such as the location of the shared library. 

The default location of this file is under the home directory as 

$HOME/.odbcinst.ini. A sample odbcinst.ini file is located in the 

$INFORMIXDIR/etc directory. 

Example 3-2 shows a simple odbcinst.ini file. 

Example 3-2 The odbcinst.ini file 

;--------------------------------------------------------------------------- 

[ODBC Drivers] 

IBM INFORMIX ODBC DRIVER=Installed 

[IBM INFORMIX ODBC DRIVER] 

Driver=/extra/informix/lib/cli/iclit09b.so 

Setup=/extra/informix/lib/cli/iclit09b.so 

APILevel=1 

ConnectFunctions=YYY 

DriverODBCVer=03.51 

FileUsage=0 

SQLLevel=1 

smProcessPerConnect=Y 

The odbinst.ini file has two sections: 

► ODBC Drivers: Lists the ODBC drivers installed in the system. 

► Driver Properties: Lists the properties for a specific ODBC driver. 

Table 3-6 lists the parameters in the Driver Properties section. 

Table 3-6 Parameters in the Driver Properties section 

Keyword Description 

Driver Location of the ODBC library 

Setup Location of the Setup library 

APILevel ODBC interface conformance level that the driver supports 

ConnectFunctions Support for SQLConnect, SQLDriverConnect, and 

SQLBrowserConnect 



DriverODBCVer Supported version of the ODBC driver 

FileUsage How handle File-system DSN 

SQLLevel Type of SQL-92 grammar supported 

The odbc.ini file 

The odbc.ini file is the data source configuration information. The default 

location of this file is under the home directory as $HOME/.odbc.ini. 

Alternatively, you can use the ODBCINI environment variable to point the 

odbc.ini to a different location. A sample odbc.ini file is located in the 

$INFORMIXDIR/etc directory. 

Example 3-3 shows a simple odbc.ini file. 

Example 3-3 The odbc.ini file 

[ODBC Data Sources] 

Infdrv1=IBM INFORMIX ODBC DRIVER 

; 

[Infdrv1] 

Driver=/extra/informix/lib/cli/iclis09b.so 

Description=IBM INFORMIX ODBC DRIVER 

Database=stores_demo 

LogonID=odbc 

pwd=odbc 

Servername=demo_on 

CursorBehavior=0 

CLIENT_LOCALE=en_us.8859-1 

DB_LOCALE=en_us.8859-1 

TRANSLATIONDLL=/extra/informix/lib/esql/igo4a304.so 

; 

[ODBC] 

;UNICODE=UCS-4 

; 

; Trace file Section 

; 

Trace=0 

TraceFile=/tmp/odbctrace.out 

InstallDir=/extra/informix 

TRACEDLL=idmrs09a.so 


This file contains three sections: 

► ODBC Data Sources: DSN name and description of the driver used 

► Data Source Specification: Configuration parameters for this particular DSN 

► ODBC: Global options such as Unicode mode or Tracing 

Table 3-7 lists the available parameters for the odbc.ini configuration file. 

Table 3-7 Parameters for the odbc.ini file 


Driver Location of the ODBC shared library 

Description DSN description 

Database Database name 

LogonID User Id 

pwd Password 

Server Database server 

CLIENT_LOCALE Locale used by the client application 

DB_LOCALE Locale of the database 

TRANSLATIONDLL Location of the code set conversion library 

CURSORBEHAVIOR Close or preserve a cursor when a 

transaction is resolved 

DefaultUDTFetchType Default type for a UDT (SQL_C_BINARY 

or SQL_C_CHAR) 

ENABLESCROLLABLECURSORS Enable Scrollable cursors 

ENABLEINSERTCURSORS Optimize insert cursors process 

OPTIMIZEAUTOCOMMIT Defer the commit message after all cursor 

are closed 

NEEDODBCTYPESONLY Extended types are mapped to standard 

ODBC types 

OPTOFC Close cursors after all the rows have been 

fetched 

REPORTKEYSETCURSORS Report support for keyset-driven cursors 

FETCHBUFFERSIZE Set the size of the fetch buffer 



DESCRIBEDECIMALFLOATPOINT Describe float types as SQL_REAL or 

SQL_DOUBLE 

USESERVERDBLOCALE Use the server database locale 

DONOTUSELVARCHAR Don’t report Lvarchar columns when using 

SQL_VARCHAR 

REPORTCHARCOLASWIDECHARCOL Char columns described by 

SQLDescribeCol are reported as Wide 

char columns (SQLWCHAR) 

ISOLATIONLEVEL Default isolation level 

UNICODE Type of Unicode (UCS-2, UCS-4) 

TRACE Trace enable or disable 

TRACEFILE Location of the trace file 

TRACEDLL Trace library name (idmrs09a.so) 

3.2.2 IBM Data Server Driver for ODBC and CLI 

The IBM Data Server Driver for ODBC and CLI (CLI Driver) is installed as part of 

the IBM Data Server Driver Package or as a separate product. The IBM Data 

Server Package is bundle with Client SDK. It allows you to connect to IBM 

Informix and IBM DB2 databases with the same set of libraries. 

The communication protocol used is DRDA instead of the native Informix SQLI. 

This driver is supported against Informix Version 11.10 and Version 11.50. 

Windows system configuration 

The IBM Data Server Driver installs in the following directory by default: 

C:\Program Files\IBM\IBM DATA SERVER DRIVER 

The ODBC driver is registered in the Windows system during the installation of 

the IBM Data Server Driver package. The name of the ODBC driver is IBM DB2 

ODBC Driver. 


Figure 3-7 shows the Drivers tab of the ODBC Data Source Administrator, which 

lists both ODBC drivers: 

► IBM DB2 ODBC DRIVER 

► IBM INFORMIX ODBC DRIVER 

Figure 3-7 ODBC Data Source Administrator 

To create an ODBC Data Source (DSN) using the IBM Data Server Driver, open 

the ODBC Administrator, choose a DSN type, and select the IBM DB2 ODBC 

Driver. 

Figure 3-8 shows the Add dialog box. 

Figure 3-8 DSN Add dialog box 


If there is no database alias defined, you must add one with the connection 

details of your IBM Informix database server (Figure 3-9). 

Figure 3-9 DSN Settings dialog box 

Figure 3-10 shows the Advanced Settings tab. 

Figure 3-10 DSN Advanced Settings dialog box 


Table 3-8 lists the minimum required parameters to connect to an Informix server. 

Table 3-8 CLI parameters 

CLI parameter Description 

Hostname Name of the system where the Informix server is running 

Port TCP Port used by the DRDA Informix alias 

Protocol Transport protocol (TCP/IP) 

Database Database server 

The configuration settings are stored as a File-DSN (a text file that contains all 

the information that is required to connect to the database) in the 

%USERPROFILE%\db2cli.ini file. Example 3-4 shows a db2cli.ini file. 

Example 3-4 The db2cli.ini file 

[test] 


Protocol=TCPIP 

Port=9089 

Hostname=kodiak 

For a complete description of all the CLI parameters, refer to the DB2 Information 

Center at: 

http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/index.jsp?topic=/com.ibm.d 

b2.luw.apdv.cli.doc/doc/r0007964.html 


On UNIX platforms, the default installation directory for IBM Data Server Client 

package is /opt/IBM/db2/V9.7. The library for the ODBC driver is libdb2.a, 

which is located in the lib directory of your Data Server installation. 

Similar to the installation on a Windows system, the ODBC configuration is 

stored in the db2cli.ini file, which by default is included in the cfg directory of 

your Data Server installation or is defined by the DB2CLIINI environment variable 


Example 3-5 shows a simple db2cli.ini file. 


[test] 



Port=9089 


For more information about the db2cli.ini file, refer to: 

http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/index.jsp?topic=/com.ibm.d 

b2.luw.apdv.cli.doc/doc/c0007882.html 

3.2.3 Verifying connectivity 

On a Windows system, you can use the ODBC Data Source Administrator to 

verify the connection with the Informix database server. 

When using the IBM Informix ODBC driver, you can verify the connection using 

the Apply & Test Connection option, as shown in Figure 3-11. 

Figure 3-11 Informix ODBC connection test 


With the IBM Data Server Driver for ODBC, you can perform the connection test 

using the Connect option, as shown in Figure 3-12. 

Figure 3-12 IBM Data Server Driver connection test 

Client SDK on UNIX does not include any tool to test an ODBC DSN. You can 

use the C samples in $INFORMIXDIR\demo\cli to check whether the ODBC DSN 

is working. 

3.3 Developing an ODBC application 

In this section, we describe how to connect to a database server, type mapping 

between standard ODBC and IBM Informix, and how to perform basic operations 

with the ODBC driver. 

3.3.1 Connecting to the database 

Typically, an ODBC application performs the following steps: 

1. Connects to the database. 

To connect to the database, the application must pass the connection details 

to the ODBC driver. These details can be included directly in the connection 

string or stored as a Data Source Name (DSN). 

2. Processes SQL statements. 


The application sends SQL request to the ODBC driver to perform database 

operations (insert, select, delete, update, and so on). 

3. Resolves any open transaction. 

If the application is using a transaction, it resolves (commits or rolls back) any 

open transactions. 

4. Terminates the connection, and frees the allocated resources. 

These steps are done using the ODBC API functions. Figure 3-13 shows a 

typical sequence of calls. The labels inside the gray boxes correspond with the 

ODBC API functions that are used. 

Figure 3-13 Typical ODBC calls used by applications 

Example 3-6 shows a simple C program that connects to an ODBC DSN. 


Example 3-6 A test_connect.c sample 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#endif 

#include "infxcli.h" 

int main (long argc, char* argv[]) 

{ 

SQLHDBC hdbc; 

SQLHENV henv; 

SQLRETURN rc = 0; 

SQLCHAR connStrIn[1000]; 

SQLCHAR connStrOut[1000]; 

SQLSMALLINT connStrOutLen; 

if (argc != 2) 

{ 

fprintf (stdout, "Please specify the name of a DSN!\n"); 

return(1); 

} 

else 

{ 

if (strstr (argv[1],"DRIVER")==NULL) 

sprintf((char *) connStrIn, "DSN=%s;", (char *)argv[1]); 

else 

sprintf((char *) connStrIn, "%s;", (char *)argv[1]); 

} 

rc = SQLAllocHandle (SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv); 

if (rc != SQL_SUCCESS) 

{ 

fprintf (stdout, "Environment Handle Allocation failed!\n"); 

return (1); 

} 

rc = SQLSetEnvAttr (henv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER) SQL_OV_ODBC3, 0); 


{ 

fprintf (stdout, "SQLSetEnvAttr failed!\n"); 

return (1); 

} 

rc = SQLAllocHandle (SQL_HANDLE_DBC, henv, &hdbc); 


{ 


} 


} 

fprintf (stdout, "Connection Handle Allocation failed!\n"); 

return (1); 

rc = SQLDriverConnect (hdbc, NULL, connStrIn, SQL_NTS, connStrOut, 1000, 

&connStrOutLen, SQL_DRIVER_NOPROMPT); 


{ 

fprintf (stdout, "Connectedion failed!\n"); 

return (1); 

} 

fprintf (stdout, "Connected\n"); 

SQLDisconnect (hdbc); 

SQLFreeHandle (SQL_HANDLE_DBC, hdbc); 

SQLFreeHandle (SQL_HANDLE_ENV, henv); 

return (rc); 

You can compile this code on a Windows system using the following command: 

cl /DWIN32 -I%INFORMIXDIR%\incl\cli odbc32.lib test_connect.c 

Example 3-7 shows how to compile and run the sample. 

Example 3-7 The test_connec.c sample output 

c:\work>cl /DWIN32 /D_CRT_SECURE_NO_DEPRECATE -I%INFORMIXDIR%\incl\cli 

odbc32.lib /nologo test_connect.c 

test_connect.c 

D:\work>test_connect 

Please specify the name of a DSN! 

D:\workt>test_connect dummy_dsn 

Connection failed! 

D:\work>test_connect test 

Connected 

D:\work>

3.3.2 Type mapping 

You can use the sample C program to perform a DSN-less connection. 

Example 3-8 shows the sample C program with a DSN-less connection string 

using the Informix ODBC driver and the Data Server driver for ODBC. 

Example 3-8 A DSN-less connection 

C:\work>test_connect "DRIVER={IBM INFORMIX ODBC 

DRIVER};SERVER=demo_on;DATABASE=stores_demo;HOST=kodiak;PROTOCOL=onsoctcp;SERVI 

CE=9088;UID=informix;PWD=password;"; 

Connected 

C:\work>test_connect "driver={IBM DB2 ODBC 

DRIVER};Database=stores_demo;hostname=kodiak;port=9089;protocol=TCPIP; 

uid=informix; pwd=password" 

Connected 

C:\work> 

The data types that are used on the database differ from the data types that are 

used by your application. This section shows the data type mapping that is 

needed when working with specific Informix data types with the Informix ODBC 

driver. 

When a query is executed by the application, the data returned by the Informix 

server might be in a different format than what the application uses. The ODBC 

driver converts the data that is passed between the application and the database 

server. This process is invisible to the application. The only requirement for the 

application is to specify the correct data types when calling the ODBC driver 

functions. 

The application sets ValueType and ParameterType when calling the bind 

functions. 

Example 3-9 shows the definition for one of the bind functions, 

SQLBindParameter(). The ODBC driver converts the data type specified in 

ValueType to the data type specified in ParameterType. 

Example 3-9 SQLBindParameter definition 

SQLBindParameter( 

SQLHSTMT StatementHandle, /* hstmt */ 

SQLUSMALLINT ParameterNumber, /* ipar */ 

SQLSMALLINT InputOutputType, /* fParamType */ 

SQLSMALLINT ValueType, /* fCType */ 

SQLSMALLINT ParameterType, /* fSqlType */ 

SQLUINTEGER ColumnSize, /* cbColDef */ 


SQLSMALLINT DecimalDigits, /* ibScale */ 

SQLPOINTER ParameterValuePtr, /* rgbValue */ 

SQLINTEGER BufferLength, /* cbValueMax */ 

SQLINTEGER *StrLen_or_IndPtr); /* pcbValue */ 

Example 3-10shows an SQLBindParameter() call where the application is binding 

an SQL_C_BINARY parameter with an SQL_INFX_UDT_FIXED value. 

Example 3-10 Using an SQLBindParameter() call 

SQLBindParameter ( 

hstmt, 

1, 

SQL_PARAM_INPUT, 

SQL_C_BINARY, 

SQL_INFX_UDT_FIXED, 

loptr_size, 

0, 

loptr_buffer, 

loptr_size, 

&loptr_valsize); 

Table 3-9 shows the Informix-specific data type mapping that is used with the 

Informix ODBC driver. 

Table 3-9 Mapping for specific Informix data types 

Informix SQL Informix ODBC driver 

BIGINT SQL_INFX_BIGINT 

BIGSERIAL SQL_INFX_BIGINT 

BLOB SQL_IFMX_UDT_BLOB 

BOOLEAN SQL_BIT 

BYTE SQL_LONGVARBINARY 

CLOB SQL_IFMX_UDT_CLOB 

DATETIME SQL_TIMESTAMP 

DISTINCT Any 

IDSSECURITYLABEL Built-in DISTINCT OF VARCHAR(128) 

INT8 SQL_BIGINT 

INTERVAL DAY SQL_INTERVAL_DAY 


Informix SQL Informix ODBC driver 

INTERVAL DAY TO HOUR SQL_INTERVAL_DAY_TO_HOUR 

INTERVAL DAY TO MINUTE SQL_INTERVAL_DAY_TO_MINUTE 

INTERVAL DAY TO SECOND SQL_INTERVAL_DAY_TO_SECOND 

INTERVAL HOUR SQL_INTERVAL_HOUR 

INTERVAL HOUR TO MINUTE SQL_INTERVAL_HOUR_TO_MINUTE 

INTERVAL HOUR TO SECOND SQL_INTERVAL_HOUR_TO_SECOND 

INTERVAL MINUTE SQL_INTERVAL_MINUTE 

INTERVAL MINUTE TO SECOND SQL_INTERVAL_MINUTE _TO_SECOND 

INTERVAL MONTH SQL_INTERVAL_MONTH 

INTERVAL SECOND SQL_INTERVAL_SECOND 

INTERVAL YEAR SQL_INTERVAL_YEAR 

INTERVAL YEAR TO MONTH SQL_INTERVAL_YEAR_TO_MONTH 

LIST, MULTISET, SET Any 

LVARCHAR SQL_VARCHAR 

MONEY SQL_DECIMAL 

NCHAR SQL_CHAR 

NVARCHAR SQL_VARCHAR 

OPAQUE (fixed) SQL_INFX_UDT_FIXED 

OPAQUE (varying) SQL_INFX_UDT_VARYING 

ROW Any 

SERIAL SQL_INTEGER 

SERIAL8 SQL_BIGINT 

TEXT SQL_LONGVARCHAR 

For a complete list of Data Type mapping, refer to the IBM Informix ODBC Driver 

Programmer’s Manual, which is available at: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.odbc.doc/si 

i04979050.htm#sii04979050 


If your application requires only Standard ODBC data types, you can enable the 

Report Standard ODBC Types option in your DSN or connection string. When 

this option is enabled, the ODBC driver handles smart large objects (BLOB and 

CLOB) as though they were simple large objects (byte and text). The driver 

generates the smart-large-object calls (ifx_lo_open, ifx_lo_write, and so on) 

automatically. 

This option changes the mapping for user define types (including MULTISET, 

SET, ROW, and LIST) to SQL_C_CHAR. 

These options are also available as the following ODBC attributes: 

► SQL_INFX_ATTR_ODBC_TYPES_ONLY 

► SQL_INFX_ATTR_LO_AUTOMATIC 

► SQL_INFX_ATTR_DEFAULT_UDT_FETCH_TYPE 

3.3.3 Performing database operations 

In this section, we show samples of how to use the ODBC driver to perform basic 

operations with an Informix database. Most of these tasks are common to any 

ODBC application, so we do not explain them in detail. 

This section includes the following topics: 

► Simple SQL statements 

► Fetching data 

► Using parameters 

► Calling SQL routines 

► Local transactions 

► Distributed transactions 

Simple SQL statements 

You can run SQL statements directly using the SQLExecDirect() function. This 

function is commonly used when there is no need to run the SQL statement more 

than once. The ODBC driver prepares the statement, executes it, and frees the 

resources in one operation. 

Example 3-11 shows a sample of using the SQLExecDirect() function to set the 

LOCK WAIT time out. 

Example 3-11 SQLExecDirect() sample, Simple_sql.c 

#include 

#include 

#include 

#ifdef WIN32 


#include 

#include 

#include 

#endif 



{ 

SQLHDBC hdbc; 

SQLHENV henv; 

SQLHSTMT hstmt; 





int sqllen; 

SQLCHAR *sqlstmt; 


{ 

fprintf (stdout, "Please specify the name of a DSN and the SQL Statement to 

run!\n"); 

return(1); 

} 

else 

{ 



else 


} 

sqllen = strlen((char *)argv[2]); 

sqlstmt = (SQLCHAR *) malloc (sqllen + sizeof(char)); 

strcpy((char *)sqlstmt, (char *)argv[2]); 



{ 

fprintf (stdout, "Environment Handle Allocation failed!\n"); 

return (1); 

} 



{ 

fprintf (stdout, "SQLSetEnvAttr failed!\n"); 

return (1); 

} 





{ 

fprintf (stdout, "Connection Handle Allocation failed!\n"); 

return (1); 

} 




{ 

fprintf (stdout, "Connection failed!\n"); 

return (1); 

} 

} 


rc = SQLAllocHandle (SQL_HANDLE_STMT, hdbc, &hstmt ); 


{ 

fprintf (stdout, "Statement Handle Allocation failed!\n"); 

return (1); 

} 

rc = SQLExecDirect (hstmt, sqlstmt, SQL_NTS); 

if (rc != SQL_SUCCESS && rc != SQL_SUCCESS_WITH_INFO) 

{ 

fprintf (stdout, "SQLExecDirectW() failed!\n"); 

return (1); 

} 

fprintf (stdout, "Executed SQL Statement:\n%s\n",sqlstmt); 




return (rc); 

Example 3-12 shows the result of running the sample program with different SQL 

statements. In this example, we input the SQL statement directly from the 

command line. In a real application, the SQL is normally constructed based on 

customer input. 

In this simple example, we also did not provide error information if the execution 

fails. You can obtain error information using the SQLGetDiagRec() function, which 

we discuss in 3.3.5, “Error handling” on page 112.

Example 3-12 Output of SQLDirectExec sample 

c:\work>cl /DWIN32 /D_CRT_SECURE_NO_DEPRECATE -I%INFORMIXDIR%\incl\cli 

odbc32.lib /nologo simple_sql.c 

simplesql.c 

c:\work>simples_sql.exe test "set lock mode to wait 10" 

Connected 

Executed SQL Statement: 

set lock mode to wait 10 

c:\work>simple_sql.exe test "create temp table temp1(c1 int)" 

Connected 


create temp table temp1(c1 int) 

c:\work>simple_sql.exe test "invalid_SQL" 

Connected 

SQLExecDirectW() failed! 

c:\work> 

Fetching data 

Example 3-13 demonstrates how to run a SELECT statement to retrieve data 

from the server. To make the code clear, we have removed all the error handling. 

Example 3-13 Select.c sample 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#endif 



{ 

SQLHDBC hdbc; 

SQLHENV henv; 






SQLCHAR sqlstmt[100]; 

SQLCHAR code[2+1]; 


} 

SQLCHAR sname[15+1]; 

SQLLEN lcode=0; 

SQLLEN lsname=0; 


sprintf((char *) connStrIn, "DSN=demo_on"); 

sprintf((char *) sqlstmt, "SELECT code, sname FROM state where code

Using parameters 

In most of the cases, an application runs the same SQL statement several times, 

so it makes sense if the SQL statement is prepared and then used with different 

values. 

Example 3-15 demonstrates how to run a simple SQL SELECT statement using 

an input parameter. The SQL statement is prepared and then executed with one 

parameter. 

Example 3-15 Example of a parametrized query, Select_param.c 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#endif 



{ 

SQLHDBC hdbc; 

SQLHENV henv; 







SQLCHAR inputcode[2+1]; 

SQLCHAR code[2+1]; 

SQLCHAR sname[15+1]; 

SQLLEN lcode = 0; 

SQLLEN lsname = 0; 

SQLSMALLINT datatype, decimaldigits, nullable; 

SQLUINTEGER paramsize; 


sprintf((char *) sqlstmt, "SELECT code, sname FROM state where code < ?"); 

sprintf((char *) inputcode, "CA"); 

SQLAllocHandle (SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv); 

SQLSetEnvAttr (henv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER) SQL_OV_ODBC3, 0); 

SQLAllocHandle (SQL_HANDLE_DBC, henv, &hdbc); 

SQLDriverConnect (hdbc, NULL, connStrIn, SQL_NTS, connStrOut, sizeof(connStrOut), 





SQLAllocHandle (SQL_HANDLE_STMT, hdbc, &hstmt ); 

SQLPrepare (hstmt, sqlstmt, strlen(sqlstmt)); 

SQLDescribeParam(hstmt, 1, &datatype, &paramsize, &decimaldigits, &nullable); 

SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT, SQL_C_CHAR, datatype, paramsize, 

decimaldigits, inputcode, 0, NULL); 

} 

SQLExecute (hstmt); 

fprintf (stdout, "Executed SQL Statement:\n%s\nUsing: '%s'\n",sqlstmt,inputcode); 

SQLBindCol (hstmt, 1, SQL_C_CHAR, &code, sizeof(code), &lcode); 

SQLBindCol (hstmt, 2, SQL_C_CHAR, &sname, sizeof(sname), &lsname); 

while ((rc = SQLFetch(hstmt))!=SQL_NO_DATA_FOUND) 

fprintf (stdout, "Fetched: %s, %s\n",code, sname); 

SQLCloseCursor(hstmt); 




return (rc); 

Example 3-16 shows the SQL statement that the program prepares and the 

parameter that is used for the placeholder. 

Example 3-16 Output for Select_param.c 

C:\work>cl /DWIN32 /D_CRT_SECURE_NO_DEPRECATE -ID:\infx\csdk350tc7\incl\cli 

odbc32.lib /nologo select_param.c 

select_param.c 

C:\work>select_param 

Connected 


SELECT code, sname FROM state where code < ? 

Using: 'CA' 

Fetched: AK, Alaska 

Fetched: AL, Alabama 

Fetched: AR, Arkansas 

Fetched: AZ, Arizona 

C:\work>

Calling SQL routines 

In this section, we demonstrate how to call an SQL routine from an ODBC 

application. The following example is a simple stored procedure that returns the 

user name and session ID: 

create procedure get_sid(user char(20)) returning char(100); 

return 'user= '||trim(user)|| ' session= '||dbinfo('sessionid'); 

end procedure; 

We use the following ODBC standard syntax for calling a database routine: 

{? = call client_routine(?, ?,...)} 

The first placeholder (?) is used only when the first parameter of the routine is an 

output parameter. If the first parameter is not an output parameter, you can run 

the routine (stored procedure or SQL function) using the following syntax: 

{call client_routine(?, ?, ?, ?)} 

Example 3-17 illustrates how to call the get_sid() SQL function. 

Example 3-17 SPL function sample, Function.c 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#endif 



{ 

SQLHDBC hdbc; 

SQLHENV henv; 







SQLCHAR errorn[20+1]; 

SQLCHAR result[100+1]; 

SQLLEN lresult = 0; 


sprintf((char *) sqlstmt, "{? = call get_sid(?)}"); 

sprintf((char *) errorn, "informix"); 










SQLBindParameter(hstmt, 1, SQL_PARAM_OUTPUT, SQL_C_CHAR, SQL_CHAR,sizeof(result),0, 

result, sizeof(result), &lresult); 

SQLBindParameter(hstmt, 2, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR, strlen(errorn),0, 

errorn, 0, NULL); 

} 

SQLExecDirect (hstmt, sqlstmt, SQL_NTS); 

SQLFetch(hstmt); 

fprintf (stdout, "Executed SQL Statement:\n%s\nUsing: '%s'\n",sqlstmt,errorn); 

fprintf (stdout, "Value returned: %s\n",result); 

SQLCloseCursor(hstmt); 




return (rc); 

Example 3-18 shows the input parameter passed to the get_sid() procedure 

and the return values. 

Example 3-18 Output of Function.c 

C:\work>cl /DWIN32 /D_CRT_SECURE_NO_DEPRECATE -ID:\infx\csdk350tc7\incl\cli 

odbc32.lib /nologo function.c 

function.c 

C:\work>function 

Connected 


{? = call get_sid(?)} 

Using: 'informix' 

Value returned: user: informix session: 213 

C:\work> 

Local transactions 

The default transaction mode for the Informix ODBC driver is auto-commit. The 

transaction is committed automatically if the SQL statement runs successfully.

You can switch to manual-commit by setting the SQL_AUTOCOMMIT_OFF 

attribute using the SQLSetConnectAttr() function. When an application sets 

SQL_AUTOCOMMIT_OFF, the next SQL statement automatically starts a 

transaction that remains open until the application calls SQLEndTran(). 

In manual mode, all the statements executed by the application are committed or 

rolled back when the application calls SQLEndTran(). 

Having auto-commit set might be more convenient when running simple SQL 

statements because there are less tasks to care about in the application code. 

However, auto-commit gives less control to the developer than using the 

manual-commit mode. When using auto-commit, there is no option to roll back a 

particular change in the database or to insert a multiple rows as a batch 

operation, which might improve the performance of the application. 

Example 3-19 illustrates how to run a local transaction in manual mode. 

Example 3-19 Transaction.c 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#endif 



{ 

SQLHDBC hdbc; 

SQLHENV henv; 







SQLINTEGER cnum = 101; 




sprintf((char *) sqlstmt, "INSERT INTO orders(order_num,order_date,customer_num) 

VALUES (0,current,?)"); 










SQLSetConnectAttr (hdbc, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_OFF, (SQLINTEGER) 

NULL); 

SQLPrepare (hstmt, sqlstmt, strlen(sqlstmt)); 

SQLDescribeParam(hstmt, 1, &datatype, &paramsize, &decimaldigits, &nullable); 

SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT, SQL_C_SHORT, datatype, paramsize, 

decimaldigits, &cnum, 0, NULL); 

} 

while (cnumcl /DWIN32 /D_CRT_SECURE_NO_DEPRECATE -ID:\infx\csdk350tc7\incl\cli 

odbc32.lib /nologo transact.c 

transact.c 

C:\work>del pp* 

C:\work>transact.exe 

Connected 


INSERT INTO orders(order_num,order_date,customer_num) VALUES (0,current,?) 

Using: '101' 

Executed SQL Statement:


Using: '102' 



Using: '103' 



Using: '104' 

Transaction Rolled back 

C:\work> 

Distributed transactions 

On a Windows system, you can run a distributed transaction using the Microsoft 

Distributed Transaction Coordinator (MSDTC) service. 

Example 3-21 demonstrates how to run a distributed transaction. The example 

opens two connections to two different database servers and enlists both 

connections into the same distributed transaction. 

Example 3-21 Transaction_dtc.cpp 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#include 

#include 

#endif 



{ 

SQLHDBC hdbc, hdbc2; 

SQLHENV henv; 

SQLHSTMT hstmt, hstmt2; 


SQLCHAR connStrIn[100],connStrIn2[100]; 









ITransactionDispenser *pTransactionDispenser = NULL; 

ITransaction * pITransaction; 

sprintf((char *) connStrIn , "DSN=server_1"); 

sprintf((char *) connStrIn2, "DSN=server_2"); 

sprintf((char *) sqlstmt, "INSERT INTO orders(order_num,order_date,customer_num) 

VALUES (0,current,101)"); 




SQLAllocHandle (SQL_HANDLE_DBC, henv, &hdbc2); 

// Get DTC 

DtcGetTransactionManager(NULL, NULL,IID_ITransactionDispenser, 0, 0, NULL, (void**) 

&pTransactionDispenser); 



fprintf (stdout, "Connected to %s\n",connStrIn); 

SQLDriverConnect (hdbc2, NULL, connStrIn2, SQL_NTS, connStrOut, sizeof(connStrOut), 


fprintf (stdout, "Connected to %s\n",connStrIn2); 

//Start the transaction on DTC 

pTransactionDispenser->BeginTransaction 

(NULL,ISOLATIONLEVEL_READCOMMITTED,0,NULL,&pITransaction); 

//Enlist the connections in distributed transaction 

SQLSetConnectAttr(hdbc, SQL_ATTR_ENLIST_IN_DTC, 

(SQLPOINTER)pITransaction,SQL_IS_INTEGER); 

SQLSetConnectAttr(hdbc2, SQL_ATTR_ENLIST_IN_DTC, 

(SQLPOINTER)pITransaction,SQL_IS_INTEGER); 



fprintf (stdout, "Executed SQL Statement:\n%s\nUsing: '%d'\n",sqlstmt,cnum); 

SQLAllocHandle (SQL_HANDLE_STMT, hdbc2, &hstmt2 ); 

if (SQLExecDirect (hstmt2, sqlstmt, SQL_NTS)!=SQL_SUCCESS) 

{ 

fprintf(stdout, "Rolling back global transaction\n"); 

pITransaction->Abort(NULL,FALSE,FALSE); 

} 

else 

{ 

pITransaction->Commit( 0, XACTTC_SYNC_PHASEONE, 0 ); 

pITransaction->Release(); 

fprintf(stdout, "Transaction Committed\n"); 

}

} 

SQLFreeHandle(SQL_HANDLE_STMT,hstmt2); 

SQLFreeHandle(SQL_HANDLE_STMT,hstmt); 

SQLDisconnect (hdbc2); 


SQLFreeHandle (SQL_HANDLE_DBC, hdbc2); 



return (rc); 

Example 3-22 shows how to compile the sample and the output of the program. 

Example 3-22 Output of Transact_dtc.cpp 

C:\work>cl /DWIN32 /D_CRT_SECURE_NO_DEPRECATE -I%INFORMIXDIR%\incl\cli 

odbc32.lib xoleHlp.lib /nologo transaction_dtc.cpp 

transaction_dtc.cpp 

C:\work>transaction_dtc 

Connected to DSN=server_1 

Connected to DSN=server_2 


INSERT INTO orders(order_num,order_date,customer_num) VALUES (0,current,101) 

Using: '101' 

Transaction Committed 

C:\work> 

Note: Remember that the DSN must be accessible to the MSDTC service. In 

Example 3-21 on page 93, test_1 and test_2 are both created as 

System-DSN. 

3.3.4 Handling special data types 

This section describes how to work with the Informix specific data types, such as 

smart large objects and complex data types. 

Smart large objects 

Smart large objects are a type of large objects supported by Informix. Smart 

large objects are logically stored in a table column but physically stored in a 

specific type of dbspaces called smart blob space (sbspace). 

The information stored in the table column is structure that contains information 

about the large object, such as the pointer to the location in the sbspace that 


contains the data or special attributes. Informix has two types of smart large 

objects. 

► BLOB: Stores binary data 

► CLOB: Stores character data 

A client application uses these data structures to perform random I/O operations 

on the large data, such as open, read, or write operations. There are two options 

for accessing smart large objects from an ODBC application: 

► Use the smart-large-object ODBC API. 

If the application requires random access to the large data, it must use the 

smart large object functions. These functions give the application a greater 

control over the smart-large-object data in terms of object properties, 

concurrency access, and logging. 

► Use smart-large-object automation. 

The ODBC driver automatically uses the ODBC API for handling large 

objects. The application can access smart large objects as standard ODBC 

data types (SQL_LONGVARBINARY and SQL_LONGVARCHAR). 

To enable smart-large-object automation use the “Report Standard ODBC 

Types Only DSN” option under the DSN Advanced tab or set the 

SQL_INFX_ATTR_LO_AUTOMATIC connection attribute. 

Data structures for smart large objects 

Table 3-10 describes the data structures used by the smart-large-object 

functions. 

Table 3-10 Smart large object data structures 

Data structure Name Description 

lofd file descriptor Defines the file descriptor to access 

smart-large-object data. 

loptr pointer structure Contains the security information and 

pointer for a smart large object. This is the 

data stored with the table columns. 

lospec specification structure Contains the storage characteristics for a 

smart large object. 

lostat status structure Contains the status information for a smart 

large object. 


Client functions to access smart large objects 

Table 3-11 lists the SQL functions that you can use in your ODBC program to 

access the Informix smart large objects. 

Table 3-11 Smart large object client functions 

Function Description 

ifx_lo_alter(loptr, lospec) Alters the storage attributes like Logging or 

Last-access 

ifx_lo_close(lofd) Closes a smart large object 

ifx_lo_col_info(colname, lospec) Updates column-level storage characteristics 

ifx_lo_create(lospec, flags, loptr, lofd) Creates and opens a new smart large object 

ifx_lo_def_create_spec(lospec) Creates a smart-large-object specification 

structure 

ifx_lo_open(lofd, loptr, flags) Opens a smart large object 

ifx_lo_read(lofd, buf) Reads data from a smart large object 

ifx_lo_readwithseek(lofd, buf, offset, 

whence) 

ifx_lo_seek(), ifx_lo_seek(lofd, offset, 

whence, seek_pos) 

ifx_lo_specget_estbytes(lospec, 

estbytes) 

Reads starting at a specific location 

Sets the file position for the next operation 

Returns the estimated size 

ifx_lo_specget_extsz(lospec, extsz) Returns the allocation extent size 

ifx_lo_specget_flags(lospec, flags) Returns create-time flags 

ifx_lo_specget_maxbytes(lospec, 

maxbytes) 

ifx_lo_specget_sbspace(lospec, 

sbspace) 

ifx_lo_specset_estbytes(lospec, 

estbytes) 

Returns the maximum number of bytes 

Returns the sbspace name 

Sets the estimated number of bytes 

ifx_lo_specset_extsz(lospec, extsz) Sets the allocation extent size 

ifx_lo_specset_flags(lospec, flags) Sets the create-time flags 

ifx_lo_specset_maxbytes(lospec, 

maxbytes) 

Sets the maximum number of bytes 



ifx_lo_specset_sbspace(lospec, 

sbspace) 

Calling client functions from ODBC 

An application must use the following standard ODBC syntax to call the 

smart-large-object functions: 

{? = call function_name (?, ?,...)} 

The following example calls the ifx_lo_open() function: 

{? = call ifx_lo_open(?, ?, ?)} 

Creating a smart large object 

To create a smart large object, you must create a BLOB descriptor and then 

insert the BLOB into the database. 

Use the following steps to create a new smart large object: 

1. Allocate memory for the specification structure using lospec. 

2. Create a lospec using ifx_lo_def_create_spec(). 

3. Initialize the specification structure using lospec. 

4. Allocate memory for the pointer structure using loptr. 

5. Create the object using ifx_lo_create(). 


Sets the sbspace name 

ifx_lo_stat(lofd, lostat) Initializes a smart-large-object status structure 

ifx_lo_stat_atime(lostat, atime) Returns the last-access time 

ifx_lo_stat_cspec(lostat, lospec) Returns the specification structure 

ifx_lo_stat_ctime(lostat, ctime) Returns the last-time change 

ifx_lo_stat_refcnt(lostat, refcount) Returns the number of references 

ifx_lo_stat_size(lostat, size) Returns the size 

ifx_lo_tell(lofd, seek_pos) Returns the current file position 

ifx_lo_truncate(lofd, offset) Truncates a smart large object at a given 

position 

ifx_lo_write(lofd, buf) Writes data 

ifx_lo_writewithseek(lofd, buf, offset, 

whence) 

Writes data at a specific location

6. Write the data into the object using ifx_lo_write(). 

7. Perform an SQL operation (INSERT, UPDATE, and so on). 

8. Close the smart large object using ifx_lo_close(). 

Example 3-23 shows how to insert a BLOB into the database. 

Example 3-23 Create_lo.c 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#include 

#include 

#endif 



{ 

SQLHDBC hdbc; 

SQLHENV henv; 



SQLCHAR connStrIn[1000], connStrOut[1000], sqlstmt[100]; 





SQLCHAR colname[25] = "catalog.advert_descr"; 

SQLINTEGER colname_size = SQL_NTS; 

SQLCHAR* file_name = (SQLCHAR *) "create_lo.c"; 

SQLCHAR* blob_data; 

SQLSMALLINT blob_size; 

SQLINTEGER blob_wsize, mode = LO_RDWR, cbMode = 0; 

int fd=0; 

struct stat statbuf; 

/* BLOB file descriptor */ 

SQLINTEGER lofd; 

SQLINTEGER lofd_valsize = 0; 

/* BLOB pointer structure */ 

SQLCHAR* loptr_buffer; 

SQLSMALLINT loptr_size; 

SQLINTEGER loptr_valsize = 0; 

/* BLOB specification structure */ 

SQLCHAR* lospec_buffer; 


SQLSMALLINT lospec_size; 

SQLINTEGER lospec_valsize = 0; 


sprintf((char *) sqlstmt, "INSERT INTO catalog(catalog_num,advert_descr) VALUES 

(0,?)"); 

/* Read the file to insert in the BLOB */ 

stat(file_name,&statbuf); 

blob_size = statbuf.st_size; 

blob_data = malloc (blob_size + 1); 

fd = _open (file_name, O_RDONLY); 

_read (fd, blob_data, blob_size); 

_close(fd); 

blob_data[blob_size] = '\0'; 

blob_wsize = blob_size; 







/* Obtain the size of the lospec and allocate memory */ 

SQLGetInfo (hdbc, SQL_INFX_LO_SPEC_LENGTH, &lospec_size, sizeof(lospec_size), NULL); 

lospec_buffer = malloc (lospec_size); 

/* Call ifx_lo_def_create_spec() to create a lospec */ 

SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT_OUTPUT, SQL_C_BINARY, 

SQL_INFX_UDT_FIXED, (UDWORD)lospec_size, 0, lospec_buffer, lospec_size, 

&lospec_valsize); 

SQLExecDirect (hstmt, (SQLCHAR *) "{call ifx_lo_def_create_spec(?)}", SQL_NTS); 

SQLFreeStmt (hstmt, SQL_RESET_PARAMS); 

/* Call ifx_lo_col_info() to initialise the lospec */ 

SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR, sizeof(colname), 

0, colname, sizeof(colname), &colname_size); 

lospec_valsize = lospec_size; 


SQL_INFX_UDT_FIXED, (UDWORD)lospec_size, 0, lospec_buffer, lospec_size, 

&lospec_valsize); 

rc=SQLExecDirect (hstmt, (SQLCHAR *) "{call ifx_lo_col_info(?, ?)}", SQL_NTS); 


/* Obtain the size of the smart loptr and allocate memory */ 

SQLGetInfo (hdbc, SQL_INFX_LO_PTR_LENGTH, &loptr_size, sizeof(loptr_size), NULL); 

loptr_buffer = malloc (loptr_size); 

/* Call ifx_lo_create() to create the BLOB */ 

SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_BINARY, SQL_INFX_UDT_FIXED, 

(UDWORD)lospec_size, 0, lospec_buffer, lospec_size, &lospec_valsize); 


c=SQLBindParameter (hstmt, 2, SQL_PARAM_INPUT, SQL_C_SLONG, SQL_INTEGER, (UDWORD)0, 

0, &mode, sizeof(mode), &cbMode); 

loptr_valsize = loptr_size; 


SQL_INFX_UDT_FIXED, (UDWORD)loptr_size, 0, loptr_buffer, loptr_size, &loptr_valsize); 

SQLBindParameter (hstmt, 4, SQL_PARAM_OUTPUT, SQL_C_SLONG, SQL_INTEGER, (UDWORD)0, 

0, &lofd, sizeof(lofd), &lofd_valsize); 

SQLExecDirect (hstmt, (SQLCHAR *) "{call ifx_lo_create(?, ?, ?, ?)}", SQL_NTS); 


/* Call ifx_lo_write to write the BLOB data */ 

SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_SLONG, SQL_INTEGER, (UDWORD)0, 0, 

&lofd, sizeof(lofd), &lofd_valsize); 

SQLBindParameter (hstmt, 2, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR, 

(UDWORD)blob_size, 0, blob_data, blob_size, &blob_wsize); 

SQLExecDirect (hstmt, (SQLCHAR *) "{call ifx_lo_write(?, ?)}", SQL_NTS); 


loptr_valsize = loptr_size; 

/* Call SQLExecDirect to do the INSERT */ 


(UDWORD)loptr_size, 0, loptr_buffer, loptr_size, &loptr_valsize); 


/* Call ifx_lo_close() to close the BLOB */ 

rc = SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER, 

(UDWORD)0, 0, &lofd, sizeof(lofd), &lofd_valsize); 

SQLExecDirect (hstmt, (SQLCHAR *) "{call ifx_lo_close(?)}", SQL_NTS); 

} 

free (lospec_buffer); 

free (loptr_buffer); 

free (blob_data); 

SQLFreeStmt (hstmt, SQL_CLOSE); 

SQLFreeHandle (SQL_HANDLE_STMT, hstmt); 




return (rc); 

Accessing a smart large object 

Reading a smart large object from the database involves the following steps: 

1. Allocate memory for the smart-large-object pointer structure (loptr). 

2. Perform the SELECT statement. 

3. Bind the smart-large-object pointer structure variable with loptr retrieved 

from the database. 


4. Call ifx_lo_open() to open the smart large object with the loptr fetched 

from the database. This step opens the smart large object on the database. 

5. Obtain the size of the smart large object status structure (lostat) and allocate 

enough memory. 

6. Call ifx_lo_stat() to obtain the BLOB status structure, so that we can 

retrieve the estimated size of the BLOB in the next step. 

7. Call ifx_lo_stat_size() to retrieve the size of the BLOB data and to allocate 

enough memory. 

8. Call ifx_lo_read() to retrieve the BLOB data. 

9. Perform any operation with the BLOB data. 

10.Call ifx_lo_close() to close the BLOB. 

Example 3-24 shows a simple application that selects a CLOB column from the 

database. 

Example 3-24 The select_lo.c application 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#include 

#include 

#endif 



{ 

SQLHDBChdbc; 

SQLHENVhenv; 

SQLHSTMThstmt; 

/* BLOB file descriptor */ 

SQLLENlofd; 

SQLLENlofd_valsize = 0; 

/* BLOB pointer structure */ 

SQLCHAR*loptr_buffer; 

SQLSMALLINTloptr_size; 

SQLLENloptr_valsize = 0; 

/* BLOB status structure */ 

SQLCHAR*lostat_buffer; 

SQLSMALLINTlostat_size; 

SQLLENlostat_valsize = 0; 

/* BLOB data */ 


SQLCHAR*lo_data; 

SQLLENlo_data_valsize = 0; 

SQLRETURNrc = 0; 

SQLCHAR*dsn = "demo_on"; 

SQLCHAR*selectStmt = (SQLCHAR *) "SELECT advert_descr FROM catalog where catalog_num 

= 10075"; 

SQLINTEGERmode = LO_RDONLY; 

SQLLENlo_size; 

SQLLENcbMode = 0, cbLoSize = 0; 




SQLConnect (hdbc, dsn, SQL_NTS, (SQLCHAR *) "", SQL_NTS, (SQLCHAR *) "", SQL_NTS); 


/* Get the size of the loptr */ 

SQLGetInfo (hdbc, SQL_INFX_LO_PTR_LENGTH, &loptr_size, sizeof(loptr_size), NULL); 

loptr_buffer = malloc (loptr_size); 

SQLExecDirect (hstmt, selectStmt, SQL_NTS); 

/* Bind the loptr with the resulset column */ 

SQLBindCol (hstmt, 1, SQL_C_BINARY, loptr_buffer, loptr_size, &loptr_valsize); 

SQLFetch (hstmt); 

SQLCloseCursor (hstmt); 

/* Call ifx_lo_open() using the loptr fetched from the database */ 

SQLBindParameter (hstmt, 1, SQL_PARAM_OUTPUT, SQL_C_LONG, SQL_INTEGER, (UDWORD)0, 0, 



(UDWORD)loptr_size, 0, loptr_buffer, loptr_size, &loptr_valsize); 

SQLBindParameter (hstmt, 3, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER, (UDWORD)0, 0, 

&mode, sizeof(mode), &cbMode); 

SQLExecDirect (hstmt, (SQLCHAR *) "{? = call ifx_lo_open(?, ?)}", SQL_NTS); 


/* Get the size of the lostat and allocate enough memory */ 

SQLGetInfo (hdbc, SQL_INFX_LO_STAT_LENGTH, &lostat_size, sizeof(lostat_size), NULL); 

lostat_buffer = malloc(lostat_size); 

/* Call ifx_lo_stat() to get the BLOB lostat */ 




SQL_INFX_UDT_FIXED, (UDWORD)lostat_size, 0, lostat_buffer, lostat_size, 

&lostat_valsize); 

SQLExecDirect (hstmt, (SQLCHAR *) "{call ifx_lo_stat(?, ?)}", SQL_NTS); 


/* Call ifx_lo_stat_size to get the size of the BLOB data and allocate enough memory*/ 



(UDWORD)lostat_size, 0, lostat_buffer, lostat_size, &lostat_valsize); 

SQLBindParameter (hstmt, 2, SQL_PARAM_OUTPUT, SQL_C_LONG, SQL_BIGINT, (UDWORD)0, 0, 

&lo_size, sizeof(lo_size), &cbLoSize); 

SQLExecDirect (hstmt, (SQLCHAR *) "{call ifx_lo_stat_size(?, ?)}", SQL_NTS); 


lo_data = malloc (lo_size + 1); 

/* Call ifx_lo_read() to get the BLOB data */ 



SQLBindParameter (hstmt, 2, SQL_PARAM_OUTPUT, SQL_C_CHAR, SQL_CHAR, lo_size, 0, 

lo_data, lo_size, &lo_data_valsize); 

SQLExecDirect (hstmt, (SQLCHAR *) "{call ifx_lo_read(?, ?)}", SQL_NTS); 

lo_data[lo_size] = '\0'; 


/* Call ifx_lo_close() to close the BLOB */ 



SQLExecDirect (hstmt, (SQLCHAR *) "{call ifx_lo_close(?)}",SQL_NTS); 

} 

fprintf(stdout,"%s",lo_data); 

free (loptr_buffer); 

free (lostat_buffer); 

free (lo_data); 






return (rc); 

Smart large object automation 

Developing an application to handle smart large objects using the smart large 

object automation method does not require any special attention. Use 

SQL_LONGBINARY and SQL_LONGVARCHAR as data type. 

Example 3-25 Illustrates how to insert a smart large object with the 

SQL_INFX_ATTR_LO_AUTOMATIC enabled. 

Example 3-25 Lo_auto.c 

#include 

#include 

#include 


#ifdef WIN32 

#include 

#include 

#include 

#include 

#include 

#endif 



{ 

SQLHDBC hdbc; 

SQLHENV henv; 


SQLCHAR* dsn="demo_on"; 


SQLCHAR str[128]; 

SQLLEN str_len = SQL_NTS; 

SQLSMALLINT BufferLength = 128; 

SQLINTEGER int_val; 







/* Set SQL_INFX_ATTR_ODBC_TYPES_ONLY connection attribute to FALSE*/ 

SQLSetConnectAttr(hdbc, SQL_INFX_ATTR_ODBC_TYPES_ONLY, (SQLPOINTER) SQL_FALSE, 

SQL_IS_UINTEGER); 

/* Set SQL_INFX_ATTR_LO_AUTOMATIC connection attribute to TRUE*/ 

SQLSetConnectAttr(hdbc, SQL_INFX_ATTR_LO_AUTOMATIC, (SQLPOINTER) SQL_TRUE, 

SQL_IS_UINTEGER); 


/* Preare the SQL statement */ 

sprintf(sqlstmt, "INSERT INTO catalog(catalog_num,advert_descr) VALUES (0,?)"); 

SQLPrepare (hstmt, sqlstmt, SQL_NTS); 

/* Bind the input parameter and Execute the SQL */ 

SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_LONGVARCHAR, 

BufferLength, 0, &str, 0, &str_len); 

SQLExecute (hstmt); 






} 


return (rc); 

Complex data types 

Rows and Collections are composite values that consist of one or more 

elements. You can use the execute SQL statements to access an entire row or 

collection. However, you cannot access individual elements within a row or 

collection. 

To access composite values from the ODBC driver you must use the Client 

functions for Rows and Collections. 

Client functions for Rows and Collections 

The ODBC functions for handling Rows and Collections start with the prefix 

ifx_rc_. Table 3-12 lists the available functions. 

Table 3-12 Row and Collection Client functions 


ifx_rc_count() Returns the number of elements or fields that are in a row or 

collection 

ifx_rc_create() Creates a buffer for a row or collection 

ifx_rc_delete() Deletes an element from a collection 

ifx_rc_describe() Returns information about the complex data type or and individual 

element 

ifx_rc_fetch() Returns the value of an element that is in a row or collection 

ifx_rc_free() Frees a row or collection handle 

ifx_rc_insert() Inserts a new element into a collection 

ifx_rc_isnull() Evaluate if a complex type is NULL or not 

ifx_rc_setnull() Set a complex type to NULL 

ifx_rc_typespec() Returns the type specification for a row or collection 

ifx_rc_update() Updates the value for an element that is in a row or collection 


Creating a complex data type 

Example 3-26 shows how to perform an INSERT operation using the Informix 

ODBC functions ifx_rc_xxx. We use a simple table customer_rc defined as 

follows: 

CREATE ROW TYPE name_t ( 

fname VARCHAR(15), 

lname VARCHAR(15) 

); 

CREATE TABLE customer_rc ( 

customer_num SERIAL, 

customer_name name_t, 

contact_dates LIST(DATETIME YEAR TO DAY NOT NULL) 

); 

Example 3-26 Create_rc.c 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#include 

#include 

#endif 



{ 

SQLHDBChdbc; 

SQLHENVhenv; 

SQLHSTMThstmt; 

/* Row variables */ 

HINFX_RChrow; 

HINFX_RChlist; 

SQLCHAR*dsn = "demo_on"; 

SQLRETURNrc = 0; 

SQLINTEGERi, in; 

SQLLENdata_size = SQL_NTS; 

SQLSMALLINTposition = SQL_INFX_RC_ABSOLUTE; 

SQLSMALLINTjump; 

SQLCHARrow_data[2][15] = {"Ludwig", "Pauli"}; 

SQLLENrow_data_size = SQL_NTS; 

SQLCHARlist_data[2][25] = {"2008-08-16","2008-08-16"}; 

SQLLENlist_data_size = SQL_NTS; 


SQLCHAR*insertStmt = (SQLCHAR *) "INSERT INTO customer_rc VALUES (0, ?, ?)"; 

SQLLENcbHrow = 0, cbHlist = 0, cbPosition = 0, cbJump = 0; 

/* Connection */ 






/* Call ifx_rc_create() to allocate a row handle */ 

SQLBindParameter (hstmt, 1, SQL_PARAM_OUTPUT, SQL_C_BINARY, SQL_INFX_RC_ROW, 

sizeof(HINFX_RC), 0, &hrow, sizeof(HINFX_RC), &cbHrow); 

SQLBindParameter (hstmt, 2, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR, 0, 0, (SQLCHAR *) 

"ROW(fname VARCHAR(15), lname VARCHAR(15))", 0, &data_size); 

SQLExecDirect (hstmt, (SQLCHAR *) "{? = call ifx_rc_create(?)}", SQL_NTS); 

/* Call ifx_rc_create() to allocate a list handle */ 

SQLBindParameter (hstmt, 1, SQL_PARAM_OUTPUT, SQL_C_BINARY, SQL_INFX_RC_LIST, 

sizeof(HINFX_RC), 0, &hlist, sizeof(HINFX_RC), &cbHlist); 


"LIST (DATETIME YEAR TO DAY NOT NULL)", 0, &data_size); 



/* call ifx_rc_update() to insert elements into the row */ 

for (i=0; i


SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_BINARY, SQL_INFX_RC_COLLECTION, 

sizeof(HINFX_RC), 0, hrow, sizeof(HINFX_RC), &cbHrow); 

SQLBindParameter (hstmt, 2, SQL_PARAM_INPUT, SQL_C_BINARY, SQL_INFX_RC_COLLECTION, 

sizeof(HINFX_RC), 0, hlist, sizeof(HINFX_RC), &cbHlist); 

SQLExecDirect (hstmt, insertStmt, SQL_NTS); 

SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_BINARY, SQL_INFX_RC_ROW, 

sizeof(HINFX_RC), 0, hrow, sizeof(HINFX_RC), &cbHrow); 

SQLExecDirect(hstmt, (SQLCHAR *)"{call ifx_rc_free(?)}", SQL_NTS); 

/* Free the list handle */ 

SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_BINARY, SQL_INFX_RC_LIST, 

sizeof(HINFX_RC), 0, hlist, sizeof(HINFX_RC), &cbHlist); 

SQLExecDirect(hstmt, (SQLCHAR *)"{call ifx_rc_free(?)}", SQL_NTS); 

} 






return (rc); 

Example 3-27 shows the information inserted into the customer_rc table after the 

execution of the example. 

Example 3-27 The customer_rc table 

> select * from customer_rc 

> ; 

customer_num 1 

customer_name ROW('Ludwig','Pauli') 

contact_dates LIST{'2008-08-16','2008-08-16'} 

1 row(s) retrieved. 

> 


Accessing a complex data type 

Example 3-28 demonstrates how to select a Row type with the ODBC driver. 

Example 3-28 The select_row.c application 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#include 

#include 

#endif 



{ 

SQLHDBC hdbc; 

SQLHENV henv; 

SQLHSTMT hstmt, hstmt_row; 

HINFX_RC hrow; 

SQLCHAR *dsn="demo_on"; 


SQLINTEGER i; 

SQLSMALLINT position = SQL_INFX_RC_ABSOLUTE, jump = 0; 

SQLLEN cbHrow = 0, cbPosition = 0, cbJump = 0, cbRCData = 0; 

SQLLEN data_size = SQL_NTS, cbrow = 0; 

SQLCHAR* sqlstmt = (SQLCHAR *) "SELECT customer_name FROM customer_rc WHERE 

customer_num = 1"; 

SQLCHAR row_data[200]; 

/* Connection */ 





SQLAllocHandle (SQL_HANDLE_STMT, hdbc, &hstmt); 

SQLAllocHandle (SQL_HANDLE_STMT, hdbc, &hstmt_row); 

/* Call ifx_rc_create() to allocate a row handle */ 

SQLBindParameter (hstmt, 1, SQL_PARAM_OUTPUT, SQL_C_BINARY, SQL_INFX_RC_ROW, 

sizeof(HINFX_RC), 0, &hrow, sizeof(HINFX_RC), &cbHrow); 


"row", 0, &data_size); 




* Bind the row handle with the resulset column */ 


SQLBindCol (hstmt, 1, SQL_C_BINARY, (SQLPOINTER) hrow, sizeof(HINFX_RC), &cbHrow); 

SQLFetch (hstmt); 

/* Get the row data */ 

fprintf(stdout, "Row data:\n"); 

for (i=0; icl /DWIN32 /D_CRT_SECURE_NO_DEPRECATE -ID:\infx\csdk350tc7\incl\cli 

odbc32.lib /nologo select_row.c 

select_row.c 

C:\work>select_row 

Row data: 


C:\work> 

3.3.5 Error handling 

Ludwig 

Pauli 

In this section, we show how to obtain additional information when an ODBC 

function fails. 

Error handling sample 

When an ODBC function fails, it stores information in the diagnostic record. This 

record contains information such as error messages, warning, and status 

information about the success or failure of the ODBC call. 

An ODBC application can retrieve the diagnostic record or individual fields using 

the SQLGetDiagRec() and SQLGetDiagField() ODBC functions. 

Example 3-30 shows a typical usage of SQLGetDiagRec(). 

Example 3-30 A sample connect_error.c application 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#endif 



{ 

SQLHDBC hdbc; 

SQLHENV henv; 





UCHAR SqlState[200] = "", ErrorMsg[200] = ""; 

SQLINTEGER IsamError = 0; 

SDWORD NativeError = 0L; 

SWORD ErrorMsgp = 0; 

SQLSMALLINT recnum = 1; 



{ 

fprintf (stdout, "Please specify the name of a DSN!\n"); 

return(1); 

} 

else 

{ 



else 


} 







{ 

SQLGetDiagRec(SQL_HANDLE_DBC, hdbc, recnum, SqlState, &NativeError, ErrorMsg, 

199, &ErrorMsgp); 

fprintf(stdout, "SqlState = %s\n Native Error = %d\n Error Message = %s\n", 

SqlState, NativeError, ErrorMsg); 

fprintf (stdout, "Connection failed!\n"); 

return (1); 

} 

} 

fprintf (stdout, "Connection Successful\n"); 




return (rc); 

Example 3-31 shows the output of Example 3-30 on page 112. In addition to the 

ODBC SQLSTATE error, it returns the Informix native error and the description 

for the error. 

Example 3-31 Output of the connect_error.c application 

C:\work>cl /DWIN32 /D_CRT_SECURE_NO_DEPRECATE -I%INFORMIXDIR%\incl\cli 

odbc32.lib /nologo connect_error.c 

connect_error.c 

C:\work>connect_error wrongDNS 

SqlState = IM002 

Native Error = 0 

Error Message = [Microsoft][ODBC Driver Manager] Data source name not found 

and no default driver specified 



C:\work>connect_error demo_on;UID=wronguser 

SqlState = 28000 

Native Error = -951 

Error Message = [Informix][Informix ODBC Driver][Informix]Incorrect password 

or user wronguser@localhost is not known on the database server. 


C:\work> 

Because this function is called quite often, it make sense to have a function to 

display the error message. Example 3-32 illustrates a typical error handling 

function. 

Example 3-32 A sample simple_select_werr.c application 

#include 

#include 

#include 

#ifdef WIN32 

#include 

#include 

#include 

#endif 


void CheckDiag (SQLSMALLINT handle_type, SQLHANDLE handle, char *text) 

{ 

RETCODErc = SQL_SUCCESS; 

UCHARSqlState[200] = "", ErrorMsg[200] = ""; 

SQLINTEGERIsamError = 0; 

SDWORDNativeError = 0L; 

SWORDErrorMsgp = 0; 

SQLSMALLINTrecnum = 1; 

fprintf (stdout,"Error in %s \n",text); 

while (rc != SQL_NO_DATA_FOUND) { 

rc = SQLGetDiagRec(handle_type, handle, recnum, SqlState, &NativeError, 

ErrorMsg, 199, &ErrorMsgp); 

if (rc != SQL_NO_DATA_FOUND) { 

SQLGetDiagField(handle_type, handle, recnum, SQL_DIAG_ISAM_ERROR, 

&IsamError, SQL_IS_INTEGER, NULL); 

fprintf (stdout," SqlState = %s\n Native Error = %d\n Error Message = %s\n 

ISAM Error = %d\n", SqlState, NativeError, ErrorMsg, IsamError); 

} 

recnum++; 

} 

} 


{ 

SQLHDBC hdbc; 


SQLHENV henv; 






int sqllen; 

SQLCHAR *sqlstmt; 


{ 

fprintf (stdout, "Please specify the name of a DSN and the SQL Statement to 

run!\n"); 

return(1); 

} 

else 

{ 



else 


} 

sqllen = strlen((char *)argv[2]); 

sqlstmt = (SQLCHAR *) malloc (sqllen + sizeof(char)); 

strcpy((char *)sqlstmt, (char *)argv[2]); 




SQLDriverConnect (hdbc, NULL, connStrIn, SQL_NTS, connStrOut, 1000, &connStrOutLen, 

SQL_DRIVER_NOPROMPT); 



} 

rc = SQLExecDirect (hstmt, sqlstmt, SQL_NTS); 

if (rc != SQL_SUCCESS && rc != SQL_SUCCESS_WITH_INFO) 

{ 

CheckDiag(SQL_HANDLE_STMT, hstmt,"SQLExecDirect()"); 

fprintf (stdout, "SQLExecDirectW() failed!\n"); 

return (1); 

} 

fprintf (stdout, "Executed SQL Statement:\n%s\n",sqlstmt); 




return (rc); 


We create a function called CheckDiag() to retrieve the diagnostic information: 

void CheckDiag (SQLSMALLINT handle_type, SQLHANDLE handle, char *text) 

Example 3-33 shows the output of the previous sample. 

Example 3-33 Output of the simple_select_werr.c application 

C:\work>simple_sql_werror demo_on "wrong sql" 

Connected 

Error in SQLExecDirect() 



Error Message = [Informix][Informix ODBC Driver][Informix]A syntax error has 

occurred. 

ISAM Error = 0 


C:\work>simple_sql_werror demo_on "DELETE from wrongtable" 

Connected 


SqlState = 42S02 


Error Message = [Informix][Informix ODBC Driver][Informix]The specified table 

(wrongtable) is not in the database. 

ISAM Error = -111 


C:\work> 

Note: If an error is generated by the database server, the error message 

contains the string [Informix] before the description of the error. For 

example: 

ODBC SQLSTATE errors with Informix ODBC Driver 

The error that is returned by the ODBC function is based on the X/Open standard 

SQLSTATE errors. For the SQLSTATE codes, refer to the Informix ODBC Driver 

Guide at: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.odbc.doc/si 

i091033222.htm#sii091033222 



SqlState = 42S02 


Error Message = [Informix][Informix ODBC Driver][Informix]The specified 

table (test) is not in the database. 

ISAM Error = -111 

SQLExecDirectW() failed!

3.3.6 Troubleshooting 

In this section, we discuss typical problems when using the Informix ODBC 

drivers and available traces. 

Environment 

Make sure the setup of Informix Client is correct. If your application fails to load 

the ODBC driver, verify that the Informix Client or Data Server Client libraries are 

accessible to the application. 

► The environment variable PATH should contain the bin directory of your Client 

package. 

► The shared library PATH variable on a UNIX system should contain the 

directory where the shared libraries are located. 

► Make sure that the INFORMIXDIR variable is set correctly (as an environment 

variable or stored in the registry using the setnet32.exe utility). 

► Any 32-bit applications require 32-bit drivers to work. Make sure that the 

drivers that you have installed are of the same type as your application. 

If your application fails to connect, make sure the connection details are valid. 

Client SDK on Windows contains a simple connection tool called iLogin, which 

you can use to check whether you have connection with the database server. If 

iLogin fails to connect, all the other drivers will fail also. 

► Check that the values stored in the registry with the setnet32.exe utility are 

valid. 

► If you use 32-bit and 64-bit drivers on the same system, remember that on a 

Windows system, there are two registry hives to store the connectivity 

information. Make sure that both are correct. 

Tracing 

When developing an application using the ODBC driver, most problems are 

caused by passing incorrect parameters to the ODBC functions. 

ODBC Trace 

You can generate a trace file of all the calls to the ODBC driver using the ODBC 

Trace facility. On a Windows system, you can enable ODBC Trace using the 

ODBC Data Source Administrator. 


Figure 3-14 shows the Tracing tab. 

Figure 3-14 Enabling trace 

Note: Remember to select Machine-Wide tracing for all user identities if 

your application runs as a service or with a different user. 

Example 3-34 shows some of the entries in an ODBC trace file. 

Example 3-34 ODBC trace 

... 

rccreate 99c-db8 EXIT SQLBindParameter with return code 0 

(SQL_SUCCESS) 

HSTMT 01D51DC0 

UWORD 2 

SWORD 1 

SWORD 1 

SWORD 1 

SQLULEN 25 

SWORD 0 

PTR 0x002CFEC8 

SQLLEN 0 

SQLLEN * 0x002CFF50 (-3) 

rccreate 99c-db8 ENTER SQLBindParameter 

HSTMT 01D51DC0 

UWORD 3 

SWORD 1 

SWORD 5 


... 

SWORD 5 

SQLULEN 0 

SWORD 0 

PTR 0x002CFF68 

SQLLEN 0 

SQLLEN * 0x002CFF54 

On a UNIX system, ODBC trace is active if the Trace parameter in the [ODBC] 

section of the odbc.ini configuration file is set to 1. 

Example 3-35 shows the Trace settings for the odbc.ini file. 

Example 3-35 Trace in the odbc.ini file 

; 

; Trace file Section 

; 

Trace=1 

TraceFile=/tmp/odbctrace.out 

InstallDir=/opt/IBM/informix 

TRACEDLL=idmrs09a.so 

SQLIDEBUG 

All the Informix clients use the SQLI protocol to communicate with the database 

server. 

In addition to the ODBC trace, you can generate an SQLIDEBUG trace that 

contains all the message between the client application and the database server. 

You can enable SQLIDEBUG trace at the Informix Client side by defining the 

environment variable as follows: 

SQLIDEBUG=2:path_to_trace_files 

Alternatively, you can enable trace at the server side by running the following 

command: 

onmode -p 1 sqli_dbg 

Note: On a Windows system, when using the server side tracing, the 

SQLIDEBUG files are created in the C:\temp\sqli directory. This directory 

must exist before you can enable the trace. 

On a UNIX system, the trace files are created in the /tmp/sqli directory. 


Example 3-36 demonstrates how to set SQLIDEBUG trace on the client. 

Example 3-36 SQLIDEBUG sample 

C:\work>set SQLIDEBUG=2:sqli_trace 

C:\work>simple_sql_werror demo_on "wrong_sql" 

Connected 




Error Message = [Informix][Informix ODBC Driver][Informix]A syntax error has 

occurred. 

ISAM Error = 0 


C:\work>dir sqli_trace_2940_1016_1f428b8 

Volume in drive C is W2003 

Volume Serial Number is 50DA-70D7 

Directory of C:\work 

22/06/2010 18:39 348 sqli_trace_2940_1016_1f428b8 

1 File(s) 348 bytes 

0 Dir(s) 76,628,099,072 bytes free 

C:\work> 

The SQLIDEBUG trace files contains the SQLI packages between the server and 

the client. To obtain an readable output, you must run the sqliprt tool. 

Example 3-37 demonstrates how to run sqliprt. 

Example 3-37 The sqliprt output 

C:\work>sqliprt -o trace.txt sqli_trace_2940_1016_1f428b8 

C:\work>type trace.txt 

SQLIDBG Version 1 

C->S (4) Time: 2010-06-22 18:39:05.43700 

SQ_INTERNALVER 

Internal Version Number: 316 

C->S (14) Time: 2010-06-22 18:39:05.43700 

SQ_PROTOCOLS 

SQ_EOT 

S->C (14) Time: 2010-06-22 18:39:05.43700 

SQ_PROTOCOLS 


SQ_EOT 

C->S (90) Time: 2010-06-22 18:39:05.43700 

SQ_INFO 

INFO_ENV 

Name Length = 12 

Value Length = 34 

"DBTEMP"="C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp" 

"SUBQCACHESZ"="10" 

"OPTOFC"="0" 

INFO_DONE 

SQ_EOT 

S->C (2) Time: 2010-06-22 18:39:05.43700 

SQ_EOT 

C->S (4) Time: 2010-06-22 18:39:05.43700 

SQ_BEGIN 

SQ_EOT 

S->C (10) Time: 2010-06-22 18:39:05.43700 

SQ_XACTSTAT 

SQ_EOT 

C->S (4) Time: 2010-06-22 18:39:05.43700 

SQ_CMMTWORK 

SQ_EOT 

S->C (10) Time: 2010-06-22 18:39:05.43700 

SQ_XACTSTAT 

SQ_EOT 

C->S (22) Time: 2010-06-22 18:39:05.43700 

SQ_PREPARE 

# values: 0 

CMD.....: "wrong_sql" [9] 

SQ_NDESCRIBE 

SQ_WANTDONE 

SQ_EOT 

S->C (12) Time: 2010-06-22 18:39:05.43700 

SQ_ERR 

SQL error..........: -201 

ISAM/RSAM error....: 0 

Offset in statement: 1 

Error message......: "" [0] 

SQ_EOT 

C:\work> 

Note: On a UNIX system, the equivalent of the sqliprt tool is sqliprint. 


DRDADEBUG 

All IBM Data Server drivers use the DRDA protocol to communicate with the 

database server. 

Similar to SQLIDEBUG, you can enable DRDADEBUG trace at the server side 

by running the following onmode command: 

onmode -p 1 drda_dbg 

The DRDA trace files are created in the /tmp/drda directory for a UNIX system 

and the C:\temp\drda directory for a Windows system. You need to use the 

drdaprint tool to convert the trace files to a readable format. 

Example 3-38 shows the use of drdaprint. 

Example 3-38 Using the drdaprint tool 

C:\temp\drda>dir 



Directory of C:\temp\drda 

22/06/2010 18:50 . 

22/06/2010 18:50 .. 

22/06/2010 18:50 2,269 drda.47 

1 File(s) 2,269 bytes 


C:\temp\drda>drdaprint 

Usage: drdaprint [-f] [-o outfile] inpfile 

-f: format hex dump 

C:\temp\drda>drdaprint -o trace.txt drda.47 

C:\temp\drda> 

Example 3-39 shows a section of the DRDA trace file. 

Example 3-39 DRDATrace file 

C:\temp\drda>type trace.txt 

DRDADBG Version 1 

1 data IDS DRDA Communication Manager 

function sqljcIntReceive() 

bytes 270 

time 2010-06-22 18:50:13.31200 

RECEIVE BUFFER(AS): 


EXCSAT RQSDSS (ASCII) (EBCDIC) 

0 1 2 3 4 5 6 7 8 9 A B C D E F 0123456789ABCDEF 0123456789ABCDEF 

0000 00C3D041000100BD 10410080115EA289 ...A.....A...^.. .C}..........;si 

0010 949793856DA29893 6DA685999996994B ....m...m......K mple_sql_werror. 

0020 85A7F0F6F1F4F0C4 F9F4F0F0F0000000 ................ ex06140D94000... 

0030 0000000000000000 0000000000000000 ................ ................ 

0040 0000000000000000 000000000060F0F0 .............`.. .............-00 

0050 F0F1C1C4D4C9D5C9 E2E3D9C1E3D6D940 ...............@ 01ADMINISTRATOR 

0060 4040404040404040 4040404040404040 @@@@@@@@@@@@@@@@ 

0070 E2E3D6D9C5E26DC4 F0C4C2F240404040 ......m.....@@@@ STORES_D0DB2 

0080 4040404040404040 40F0001814041403 @@@@@@@@@....... 0...... 

0090 000A2407000A1474 0005240F00081440 ..$....t..$....@ ............... 

00A0 0009000B1147D8C4 C2F261D5E3000A11 .....G....a..... ......QDB2/NT... 

00B0 6DC4E4C2C9E3D600 0C115AE2D8D3F0F9 m.........Z..... _DUBITO...]SQL09 

00C0 F0F7F0 ... 070 



Chapter 4. Working with ESQL/C 

This chapter discusses ESQL/C, an SQL application programming interface 

(API) that enables you to embed Structured Query Language (SQL) statements 

directly into a C program. ESQL/C is bundled with the Informix Client Software 

Development Kit (Client SDK). The ESQL/C preprocessor, esql, converts each 

SQL statement and all IBM Informix-specific code to C-language source code 

and invokes the C compiler to compile it. 

The advantage of using ESQL/C is that it supports all the data types as well as 

extended data types of Informix and is optimized for an IBM Informix database. If 

you are using only Informix as your database server, then using ESQL/C might 

be your best choice. 

In this chapter, we discuss the basic elements of an Informix ESQL/C application 

and show how to perform database operations within an ESQL/C program. We 

end the chapter by looking at various methods in handling exceptions and 

troubleshooting. 


► Informix ESQL/C 


► Windows system configuration 

► Developing an ESQL/C application 

4 


4.1 Informix ESQL/C 

Informix ESQL/C includes the following software components: 

► The Informix ESQL/C libraries of C functions, which provide access to the 


► The Informix ESQL/C header files, which provide definitions for the data 

structures, constants, and macros that are useful to the Informix ESQL/C 

program 

► The esql command, which processes the Informix ESQL/C source code to 

create a C source file that it then passes to the C compiler 

► The finderr utility on the UNIX system and the Informix Error Messages 

Windows-based Informix error messages utility that enable you to obtain 

information about IBM Informix-specific error messages 

On Windows platforms, Informix provides the following additional utilities: 

► The setnet32.exe utility, which is a Windows-based utility that enables you to 

set configuration information 

► The iLogin utility, which is a demonstration program that displays a dialog box 

with fields for the connection parameters and for testing a connection to the 

database server (uses the stores7 database) 

Figure 4-1 gives an overview of the relationship between ESQL/C and the native 

C and illustrates the process of the transfer of control. 

Figure 4-1 Relationship between Informix ESQL/C and C 

When you have created an Informix ESQL/C program file, you run the esql 

command on that file. By default, the Informix ESQL/C preprocessor runs first 

and translates the embedded SQL statements in the program into Informix 

ESQL/C function calls that communicate with the database server. The Informix 

ESQL/C preprocessor produces a C source file and calls the C compiler. The C 

compiler then compiles your source file and links any other C source file, object 

file, or library file the same way as any other C program. 


If the esql command does not encounter errors in one of these steps, it 

generates an executable file. You can run the compiled Informix ESQL/C 

program as you would run any C program. When the program runs, it calls the 

Informix ESQL/C library procedures. The library procedures set up 

communications with the database server to carry out the SQL operations. 


Informix ESQL/C is installed, by default, as a part of Client SDK. The release 

notes for Client SDK contain the information about supported versions of the IBM 

Informix database server. Make sure that you install the version of Client SDK 

that is supported by the database with which you are working. 

4.3 Windows system configuration 

On a Windows system, the default Client SDK installation directory is C:\Program 

Files\IBM\Informix\Client-SDK. Make sure that the INFORMIXDIR 

environment variable is pointing to the directory where the product was installed. 

The PATH environment variable needs to contain the following directories: 

► The path to the bin directory that is under the installation directory needs to 

be defined (that is, the PATH variable needs the $INFORMIXDIR/bin directory 

defined). 

► The path where native C compiler is located. Informix Client products are 

certified with the Microsoft Visual C++ 2005 SP1. 


On UNIX platforms, the default installation directory for Client SDK is 

/opt/IBM/informix. The INFORMIXDIR environment variable needs to point to 

the directory where the product was installed. Add the following directories to the 

PATH environment variable: 

► The bin directory under the installation directory, $INFORMIXDIR/bin 

► The path to the native C compiler 

The sqlhosts file contains the information that is required to connect to an IBM 

Informix database server. You must set this file to include an entry for your 

Informix database server name, ESQL/C required protocol, host name, and port 

number. By default, the sqlhosts file is under the $INFORMIXDIR/etc/ directory. 

You can use the INFORMIXSQLHOSTS environment variable to point to a 

different location. 

Chapter 4. Working with ESQL/C 127

Example 4-1 shows a simple sqlhosts file. 

Example 4-1 The sqlhosts file 


demo_on onsoctcp kodiak 9088 

For more information about the sqlhosts file, refer to: 



4.4 Developing an ESQL/C application 

In this section, we describe how to connect to a database, how to perform basic 

database operations such as delete and insert, and how to update using 

ESQL/C. We also describe the handling of extended data types by ESQL/C. 

We use the sample instance and database that Informix Server provides to 

demonstrate ESQL/C application development. The sample instance, demo_on, is 

created when the Informix server is installed. On a Windows operating system, 

the sample instance is ol_svr_custom. You can create a sample database, 

stores_demo, under the demo_on instance and populate that sample database 

with tables and data by running the dbaccessdemo utility that resides in the 

$INFORMIXDIR/bin/ directory. 

4.4.1 Creating an ESQL/C application 

To build an Informix ESQL/C application: 

1. Develop a C program with the embedded Informix SQL statements, and name 

the program with a .ec or .ecp extension. The SQL statements are qualified 

with an EXEC SQL keyword or the dollar sign ($) symbol as shown in the 

following example: 

EXEC SQL include sqlca; 

EXEC SQL SELECT fname into :c1 FROM customer WHERE customer_num=:i1 

$SET ISOLATION DIRTY READ; 

2. Preprocess the Informix ESQL/C source file with the esql command. The 

esql command also invokes the C compiler to compile the program into object 

code. 

As necessary, correct errors that are reported by the preprocessor and the 

compiler and then repeat this step. 


3. Link the object code into one or more executable files using the esql 

command. The executable files have a .exe extension. 

4. Run the application. 

You run the compiled Informix ESQL/C program as you would any C program. 

When the program runs, it calls the Informix ESQL/C library procedures. The 

library procedures set up communications with the database server to carry 

out the SQL operations. 

Example 4-2 shows a simple program, customer.ec, that connects to the 

database and retrieves data. All the SQL-related statements are embedded in 

the C program with the EXEC SQL keyword. 

Example 4-2 Simple ESQL/C program 

#include 


EXEC SQL include sqltypes; 

int main() 

{ 

EXEC SQL BEGIN DECLARE SECTION; 

int i1=101; 

char c1[50]; 

char c2[50]; 

EXEC SQL END DECLARE SECTION; 

int i2; 

EXEC SQL connect to 'stores_demo'; 

EXEC SQL select fname,lname into :c1, :c2 from customer where 

customer_num=:i1 

; 

if (SQLCODE == 100) 

{ 

printf("SQLCODE=%d\n",SQLCODE); 

printf("Data not found\n"); 

} 

else 

{ 


printf("Data found \n"); 

printf("Last Name \t%s\n",c1); 

printf("First Name \t%s\n",c2); 

} 

} 


Compiling ESQL/C programs 

The esql command translates Informix ESQL/C code to C code and then calls 

the C compiler to compile and link the C code. 

The C compiler takes the following actions: 

1. Compiles the C language statements to object code. 

2. Links to Informix ESQL/C libraries and to any other files or libraries that you 

specify. 

3. Creates an executable file. 

The general syntax for an esql command to compile is as follows: 

esql 

By default, the esql command creates an executable called a.out in the current 

directory. You can explicitly specify the name of the executable file with the -o 

option. For example, the following command compiles the customer.ec 

executable file shown in Example 4-2 on page 129 and produces the executable 

file customer.exe: 

esql -o customer.ec customer.exe 

If you run the esql command on a Windows operating system, the name of the 

target file defaults to the name of the first Informix ESQL/C source file on the 

esql command line. The extension is changed to either .exe or .dll, depending 

on the type of target that is generated. 

You can use a compiler other than the native C compiler by setting the 

INFORMIXC environment variable. Table 4-1 lists the native C compilers on 

various platforms. 

Table 4-1 Native C compiler 

Platforms Native compiler 

Solaris CC 

HP aC++ 

Windows VC++ / VS2008/ VS2005 

AIX xlc 

Open source gcc/g++ 

If you want to pass C compiler options that have the same names as Informix 

ESQL/C processor options, precede them with the -cc option. For example, the 


following esql command passes the -od and -g options to the C compiler but 

uses the -db2 option itself: 

esql -cc -od -g demo1.ec -db2 

Shared libraries 

IBM Informix products use the Informix general libraries for interactions between 

the client SQL API products (IBM Informix ESQL/C and IBM Informix 

ESQL/COBOL) and the database server. You can choose between the following 

types of Informix general libraries to link with your Informix ESQL/C application: 

► Static Informix general libraries 

To link a static library, the linker copies the library functions to the executable 

file of your Informix ESQL/C program. The static Informix general libraries 

allow an Informix ESQL/C program on computers that do not support shared 

memory to access the Informix general library functions. 

To link static libraries use the -static option, for example: 

esql -static file.ec -o file.exe 

► Shared Informix general libraries 

To link a shared library, the linker copies information about the location of the 

library to the executable file of your Informix ESQL/C program. The shared 

Informix libraries allow several applications to share a single copy of these 

libraries, which the operating system loads just once into shared memory. 

► Thread-safe versions of static and shared Informix general libraries 

The thread-safe versions of Informix general libraries allow an Informix 

ESQL/C application that has several threads to call these library functions 

simultaneously. The thread-safe versions of Informix libraries are available as 

both static libraries and shared libraries. 

There are some platform specific considerations when you link shared Informix 

general libraries to an ESQL/C module. The environment variable that specifies 

the search path at run time is different depending on the platform, as listed in 

Table 4-2. 

Table 4-2 Environment variable for shared libraries 

Platform Environment variable 

AIX LIBPATH 

Solaris LD_LIBRARY_PATH 

HP-UX SHLIB_PATH 

Mac OS X DYLD_LIBRARY_PATH 


Platform Environment variable 

Linux LD_LIBRARY_PATH 

Windows LIB 

Set the $INFORMIXDIR/lib directory and any of its subdirectories to specify the 

shared-library path. For example, on Linux, set the LD_LIBRARY_PATH 

environment variable as follows: 

► Bourne shell 

LD_LIBRARY_PATH=$INFORMIXDIR/lib:$LD_LIBRARY_PATH 

export LD_LIBRARY_PATH 

► C shell 

setenv LD_LIBRARY_PATH $INFORMIXDIR/lib:$LD_LIBRARY_PATH 

On a Windows system, use the following command: 

set LIB = %INFORMIXDIR%\lib\;%LIB% 

To link shared Informix general libraries with an Informix ESQL/C module, you do 

not need to specify a command-line option. Informix ESQL/C links shared 

libraries by default. The following command compiles the file.ec source file with 

shared Informix libraries: 

esql myfile.ec -o myfile.exe 

Choosing between shared and static library versions 

Shared libraries are most useful in multiuser environments where only one copy 

of the library is required for all applications. Shared libraries bring the following 

benefits to your Informix ESQL/C application: 

► Shared libraries reduce the size of executable files because these library 

functions are linked dynamically on an as-needed basis. 

► At run time, a single copy of a shared library can be linked to several 

programs, which results in less memory use. 

► The effects of shared libraries in an Informix ESQL/C executable are 

transparent to the user. 

Although shared libraries save both disk and memory space, when an Informix 

ESQL/C application uses them, it must perform the following overhead tasks: 

► Dynamically load the shared library into memory for the first time 

► Perform link-editing operations 

► Execute library position-independent code 


These overhead tasks can incur runtime penalties and are not necessary when 

you use static libraries. 


In this section, we discuss how to perform basic database operations in an 

ESQL/C application: 

► Database connections 

► Simple SQL statements (SELECT, INSERT, UPDATE, and DELETE) 

► Static and dynamic SQL 

► Calling SQL routines (stored procedures) 

► Using transactions 

In the program, we try to make use of most commonly used data types. For 

information about other data types, refer to: 


esqlc.doc/sii-03-sourceforchaptitle.htm 

Database connections 

When an Informix ESQL/C application executes, it has no connections to any 

database server. For SQL statements to run, however, such a connection must 

exist. To establish a connection to a database server, the Informix ESQL/C 

program must take the following actions: 

1. Use an SQL statement to establish a connection to the database server. 

2. Specify, in the SQL statement, the name of the database server to which to 

connect. 

The client application connects to the default database server when the 

application does not explicitly specify a database server for the connection. You 

must set the INFORMIXSERVER environment variable even if the application 

does not establish a connection to the default database server. 

If user name and password are not explicitly specified using the InetLogin 

structure or the USER clause, the default user ID is used to attempt the 

connection. The default user ID is the login name of the user who is running the 

application. 


Example 4-3 shows a statement that connects to the stores_demo database 

under the demo_on instance. 

Example 4-3 Database connection statement 

EXEC SQL connect to 'stores_demo@demo_on'; 

EXEC SQL connect to stores_demo user :username using :password; 

For more information about database connections in ESQL/C, refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.esqlc.doc/s 

ii12164286.htm#sii12164286 


There are several way to execute an SQL statement from an ESQL/C application. 

The application must choose an appropriate method based on the nature of the 

SQL statement. 

► SQL statements that do not return a result set of data such as INSERT, 

DELETE, UPDATE, or Data Definition Language (DDL) can be executed 

using the EXEC SQL command (same as the $ prefix) or the EXEC SQL 

execute immediate statement. Both methods produce the same C code. 

EXEC SQL execute immediate :cmdstring; 

$CREATE TABLE my_customer (fname char(20)); 

If the SQL statement is going to be executed more than one time during the 

life of the application, it can be prepared with the EXEC SQL PREPARE 

command and then executed when required using the EXEC SQL EXECUTE 

command: 

EXEC SQL prepare d_id from :stmt_buf; 

EXEC SQL execute d_id; 

► SQL statements that return one row can be executed using the EXEC SQL 

EXECUTE INTO command. These types of statement are normally referred 

as singleton statements. 

EXEC SQL SELECT specs into :mspecs FROM my_customer WHERE customer_num=2; 

► SQL statements that return more than one row are executed using a select 

cursor: 

EXEC SQL declare cursor1 cursor for SELECT fname into :var1 from customer; 

EXEC SQL open cursor1; 

EXEC SQL fetch cursor1; 


Example 4-4 demonstrates how to execute an SQL statement using some of 

these previously described methods. 

Example 4-4 Simple SQL statements (INSERT, UPDATE, and DELETE) 

#include 

#include 



int main() 

{ 


char cmdstring[4096]; 

string *fname[5] = { "Ludwig","Carole", "Philip", "Anthony", "Raymond" }; 

string *lname[5] = { "Pauli", "Sadler", "Currie", "Higgins", "Vector" }; 

string *company[5] = {"All Sports Supplies","Sports Spot", "Phil's Sports", "Play 

Ball!", "Los Altos Sports" }; 

char pref='t'; 

char *specs[5] = { "This is just any string ", "This is just another string ", 

"This is the third string", "This is one more string", "This is the last string"}; 

lvarchar mspecs[250]; 

char *order_date[5] = {"08/01/77","08/02/77","08/03/77","08/04/77","08/05/77"}; 

float ship_charge[5] = {10000.59,590000.32,345577.12,987098.32,876893.22}; 

char *ship_duration[5] = {"10:10:10","11:11:11","22:22:22","33:33:33","44:44:44"}; 


$WHENEVER ERROR STOP; 

int i; 


$ CREATE TABLE my_customer ( 

customer_num bigserial, 

fname char(15), 

lname char(15), 

company char(30), 

preferred boolean, 

specs lvarchar 

); 

$ CREATE TABLE my_orders ( 

order_num bigserial, 

order_date date , 

customer_num bigint, 

ship_charge money(10,2), 

ship_duration INTERVAL hour to second 

); 

for (i = 0; i < 5 ; i++) 

{ 

$INSERT INTO my_customer VALUES ( 

0, 


:fname[i], 

:lname[i], 

:company[i], 

:pref, 

:specs[i] 

); 

} 

for (i = 0; i < 5 ; i++) 

{ 

sprintf(cmdstring, "INSERT INTO my_orders VALUES (10000001,'%s',%d,%f,'%s' );", 

order_date[i], i,ship_charge[i], ship_duration[i]); 


} 

sprintf(cmdstring, "UPDATE my_customer SET specs='This is a new spec' WHERE customer_num 

= 2"); 


if (SQLCODE != 0) 


sprintf(cmdstring, "DELETE FROM my_customer where customer_num=3"); 




EXEC SQL SELECT specs into :mspecs FROM my_customer WHERE customer_num=2; 



else 

printf("The spec for the customer is :%s\n", mspecs); 

} 

For additional information regarding the execution of SQL statements, refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.e 

sqlc.doc/esqlc298.htm 

Static and dynamic SQL 

The SQL statements shown in Example 4-4 on page 135 are all static SQL 

statements. With a static SQL statement, all the information that is needed is 

known at compile time. However, in some applications the programmer does not 

know the contents or possibly even the types of SQL statements that the 

program needs to execute. For example, a program might prompt the user to 

enter a SELECT statement, so that the programmer has no idea what columns 

are accessed when the program runs. 

Such applications require dynamic SQL statements. Dynamic SQL statements 

allow an IBM Informix ESQL/C program to build an SQL statement at run time, so 

that the contents of the statement can be determined by user input. 


Example 4-5 shows how to use dynamic SQL in a program. 

Example 4-5 Dynamic SQL statements 

#include 



int main() 

{ 


int i1; 


char c1[50]; 

char c2[50]; 


int i2; 


printf("Enter the customer number [101-128] to see the names:"); 

scanf("%d", &i1); 

sprintf (cmdstring, "SELECT fname,lname from customer where customer_num = ?"); 

EXEC SQL prepare ex_id from :cmdstring; 

EXEC SQL execute ex_id into :c1,:c2 using :i1; 

; 


{ 



} 

else 

{ 


printf("Data found \n"); 

printf("Last Name \t%s\n",c1); 

printf("First Name \t%s\n",c2); 

} 

} 

OUTPUT: 

Enter the customer number [101-128] to see the names:102 

SQLCODE=0 

Data found 

Last Name Carole 

First Name Sadle 


The SELECT statement shown in Example 4-5 on page 137 is called a singleton 

SELECT statement because it returns only one row. For SELECT statements 

that return multiple rows, you must use a SELECT cursor statement. 

Example 4-6 shows how to use cursor for SELECT statements that return 

multiple rows. 

Example 4-6 Using cursor for SELECT statements that return multiple rows 

#include 



int main() 

{ 


int i; 


char c1[50]; 

char c2[50]; 



printf("Enter customer number [103 - 128] :"); 

scanf("%d", &i); 

sprintf (cmdstring, "SELECT fname,lname from customer where customer_num < ?;"); 


EXEC SQL declare ex_cursor cursor for ex_id; 

EXEC SQL open ex_cursor using :i; 

/* Print out what DESCRIBE returns*/ 

for (;;) 

{ 

EXEC SQL fetch ex_cursor into :c1,:c2; 

if (strncmp(SQLSTATE, "00", 2) != 0) 

break; 


{ 



} 

else 

{ 

printf("%s\t%s\n",c1,c2); 

} 

} 

OUTPUT: 

Enter customer number [103 - 128] : 108 

Ludwig Pauli 

Carole Sadler 

Philip Currie 


Anthony Higgins 

Raymond Vector 

George Watson 

Charles Ream 

For more details about dynamic SQL and the cursors, refer to: 


ii-sc3dysq-35492.htm#sii-sc3dysq-35492 

Calling SQL routines 

In this section, we demonstrate how to call an SQL routine from an ESQL/C 

application. You can accomplish a wide range of objectives with SQL routines, 

including improving database performance, simplifying writing applications, and 

limiting or monitoring access to data. Because an SQL routine is stored in an 

executable format, you can use it for repeated tasks to improve performance. 

When you invoke an SPL routine, rather than straight SQL code, you can bypass 

repeated parsing, validity checking, and query optimization. 

Example 4-7 shows a simple program that contains an SPL routine that receives 

arguments price and percent tax and that returns price after adding the tax. 

Example 4-7 Calling SQL routines 

#include 

$ INCLUDE sqlca.h; 

$ INCLUDE sqltypes.h; 

int main() 

{ 



float n1,n2; 

int i=2; 


EXEC SQL whenever sqlerror stop; 

EXEC SQL CONNECT TO 'stores_demo'; 

sprintf(cmdstring, "CREATE FUNCTION inc_price(n1 money(8,2), n2 int) RETURNING 

money(8,2) RETURN(n1 + (n1 *n2)/ 100); END FUNCTION;"); 


sprintf(cmdstring, "SELECT FIRST 5 total_price, inc_price(total_price,?) from items ;"); 


EXEC SQL declare ex_cursor cursor for ex_id; 

EXEC SQL open ex_cursor using :i; 

/* Print out what DESCRIBE returns*/ 

for (;;) 

{ 


EXEC SQL fetch ex_cursor into :n1,:n2; 

if (strncmp(SQLSTATE, "00", 2) != 0) 

break; 


{ 



} 

else 

{ 

printf("%f\t%f\n",n1,n2); 

} 

} 

} 

OUTPUT: 

250.000000 255.000000 

960.000000 979.200012 

240.000000 244.800003 

20.000000 20.400000 

840.000000 856.799988 

Using transactions 

A transaction is a collection of SQL statements that are treated as a single unit of 

work. All the SQL statements that you issue in an ANSI-compliant database are 

contained in transactions automatically. With a database that is not ANSI 

compliant, transaction processing is an option. 

In a database that is not ANSI compliant, a transaction is enclosed by a BEGIN 

WORK statement and a COMMIT WORK or a ROLLBACK WORK statement. In 

an ANSI-compliant database, the BEGIN WORK statement is unnecessary, 

because all statements are contained in a transaction automatically. You need to 

indicate only the end of a transaction with a COMMIT WORK or ROLLBACK 

WORK statement. 

Example 4-8 shows an example using transactions. 

Example 4-8 Using transactions 

#include 

$include "sqlca.h"; 

$include "sqlhdr.h"; 

$include "sqltypes.h"; 

main() 

{ 



int n1; 

char c1[20]; 



EXEC SQL CREATE DATABASE itso WITH LOG; 

EXEC SQL CREATE TABLE t1(num serial, name char(20)); 

EXEC SQL BEGIN WORK; 

EXEC SQL INSERT INTO t1 VALUES (0,'name1'); 



EXEC SQL ROLLBACK; 

EXEC SQL BEGIN WORK; 



EXEC SQL COMMIT; 

EXEC SQL declare ifx_cursor cursor for select num,name into :n1,:c1 from t1; 

EXEC SQL open ifx_cursor ; 

for (;;) 

{ 

EXEC SQL fetch ifx_cursor; 

if (sqlca.sqlcode!=0) 

break; 

printf("%d\t%s\n",n1,c1); 

} 

EXEC SQL close ifx_cursor; 

EXEC SQL free ifx_cursor; 

} 

OUTPUT: 

4 name4 

5 name5 

4.4.3 Data types mapping 

This section contains information about the correspondence data types between 

SQL and C and how to handle data types in an IBM Informix ESQL/C program. 

When a query is executed by the application, the data that the Informix server 

returns might be in a different format than the format that the application uses. 

The ESQL/C converts the data passed between the application and the 

database server. This process is transparent to the application. The only 

requirement for the application is to specify the correct data types in ESQL/C. 


Table 4-3 lists a few ESQL/C data type mapping as examples. 

Table 4-3 Informix data type mapping 

Informix SQL ESQL/C 

BOOLEAN boolean 

BYTE loc_t 

LVARCHAR lvarchar 

NCHAR(n) fixchar [n] or string [n+1] 

NVARCHAR(m) varchar[m+1] or string [m+1] 

SERIAL8 int8 or ifx_int8_t 

TEXT loc_t 

BLOB ifx_lo_t 

CLOB ifx_lo_t 

LIST(e) collection 

MULTISET(e) collection 

Opaque data type lvarchar, fixed binary, or var binary 

ROW(...) row 

SET(e) collection 

For a complete list of all the Informix SQL to ESQL/C data type mapping, refer to: 


esqlc.doc/sii03147680.htm 

4.4.4 Handling special data types 

This section describe how to work with Informix specific data types. We discuss 

the following data types: 

► Smart large objects (BLOB and CLOB) 

► Collection data types (LIST, MULTISET, and SET) 

► ROW data type 

To store large objects inside database, you can use data types such as TEXT, 

BYTE, BLOB, and CLOBS. Informix supports simple large objects and smart 

large objects. Simple large objects are the TEXT and BYTE types that exist 

primarily for compatibility with earlier versions of Informix applications. The smart 


large objects are the BLOB and CLOBs. When you write new applications that 

need to access large objects, use smart large objects to hold character (CLOB) 

and binary (BLOB) data. 

Table 4-4 summarizes the advantages that smart large objects present over 

simple large objects. 

Table 4-4 Advantages of smart blobs over simple blobs 

Large object feature Simple large objects Smart large objects 

Maximum size of data 2 gigabytes 4 terabytes 

Data accessibility No random access to data Random access to data 

Reading the large object The database server reads 

a simple large object on an 

all or nothing basis. 

Writing the large object The database server 

updates a simple large 

object on an all or nothing 

basis. 

Library functions provide 

access that is similar to 

accessing an 

operating-system file. You 

can access specified 

portions of the smart large 

object. 

The database server can 

rewrite only a portion of a 


Data logging Data logging is always on. Data logging can be turned 

on and off. 

Example using CLOB and BLOBs 

Informix ESQL/C supports the SQL data types CLOB and BLOB with the 

ifx_lo_t data type. Because of the potentially huge size of smart large object 

data, the Informix ESQL/C program does not store the data directly in a host 

variable. Instead, the client application accesses the data as a file-like structure. 

To use smart large object variables in an Informix ESQL/C program, take the 

following actions: 

1. Declare a host variable with the ifx_lo_t data type. 

2. Access the smart large object with a combination of the following three data 

structures: 

– The LO-specification structure, ifx_lo_create_spec_t 

– The LO-pointer structure, ifx_lo_t 

– An integer LO file descriptor 

Smart large objects are stored logically in a table column but stored physically in 

a specific type of dbspaces called smart blob space (sbspace). You must create 


the sbspace in the server before you can run this example. For details about 

creating the sbspace, refer to: 



Example 4-9 illustrates how to work with BLOB and CLOB data types using 

ESQL/C functions. The filetoclob and filetoblob functions are used to enter 

the CLOB and BLOB data respectively. If your files are located on the client 

system, then use the client name as the second argument to the filetoblob 

function. If your files are located on the server system, then use the server name 

as the second argument. 

The output is a part of the file that you insert as a BLOB. In this example, we 

used a readme.txt file. 

Example 4-9 The ifx_lo_sample.ec file 

#include 

$include "sqlca.h"; 

$include "sqlhdr.h"; 

$include "sqltypes.h"; 

main() 

{ 

int error, ic1, oflags, cflags, extsz, imsize, isize, iebytes; 

time_t time; 

struct tm *date_time; 

char col_name[300]="test", sbspc[129]; 


fixed binary 'blob' ifx_lo_t c2; 

char srvr_name[256]; 

ifx_lo_create_spec_t *cspec; 

ifx_lo_stat_t *stats; 

ifx_int8_t size, c1, estbytes, maxsize; 

int lofd; 

long atime, ctime, mtime, refcnt; 




EXEC SQL create table t2 (c1 int, c2 blob); 

EXEC SQL insert into t2 values (1,filetoblob ('/tmp/README.txt', 'server','t2','c2')); 

EXEC SQL declare ifxcursor cursor for select c1,c2 into :c1,:c2 from t2 for update; 

EXEC SQL open ifxcursor; 

for (;;) 

{ 


EXEC SQL fetch ifxcursor; 

if (sqlca.sqlcode!=0) 

break; 

lofd = ifx_lo_open(&c2, LO_RDWR, &error); 

ifx_lo_read(lofd, srvr_name, 256, &error); 

printf("Value: %s\n",srvr_name); 

ifx_lo_write(lofd,col_name,5,&error); 

ifx_lo_close(lofd); 

} 

EXEC SQL close ifxcursor; 

EXEC SQL free ifxcursor; 

ifx_lo_close(lofd); 

} 

For more information about the ESQL/C functions to create, alter, and access 

BLOB and CLOB data, refer to: 


esqlc.doc/sii-03-sourceforchaptitle.htm 

Example using collection data types 

Collection data types (SET, LIST, and MULTISET) enable you to store and 

manipulate collections of data within a single row of a table. A collection data 

type has two components: 

► A type constructor, which determines whether the collection type is a SET, 

MULTISET, or LIST 

► An element type, which specifies the type of data that the collection can 

contain 

The elements of a collection can be of any data type. The elements of a 

collection are the values that the collection contains. In a collection that contains 

the values {'blue', 'green', 'yellow', and 'red'}, blue represents a single 

element in the collection. Every element in a collection must be of the same type. 

For example, a collection whose element type is INTEGER can contain only 

integer values. 

Informix ESQL/C uses collection variables to access collection data types. A 

collection variable stores the elements from a collection column as though they 

were rows in a table. You can use this virtual table as part of a cursor declaration 

to fetch the individual elements of the collection column. 


Example 4-10 shows the ESQL/C commands that are used to retrieve an 

element from a collection column. The parents column is a collection of INT 

values. The collection is stored into the host variable hv1 and is used to open a 

cursor using the variable as a virtual table, table(:hv1). 

Example 4-10 The collection_sample 

EXEC SQL client collection hv1; 

EXEC SQL int parent_id; 

EXEC SQL select parents into :hv1 from grade12_parents where class_id = 1; 

EXEC SQL declare cur1 cursor for select id from table(:hv1); 

EXEC SQL open cur1; 

EXEC SQL fetch cur1 into :parent_id; 

The INT elements of the collection are retrieved from the host variable using the 

EXEC SQL fetch cur1 command. 

Example 4-11 shows a complete ESQL/C program that illustrates how to insert 

and select into tables that contain the collection data types. 

Example 4-11 Example using collection types 

#include 

static void print_collection( 

const char *tag, 


parameter client collection c 


) 

{ 


int4 value; 


mint item = 0; 

} 


EXEC SQL WHENEVER ERROR STOP; 

printf("COLLECTION: %s\n", tag); 

EXEC SQL DECLARE c_collection CURSOR FOR 

SELECT * FROM TABLE(:c); 

EXEC SQL OPEN c_collection; 

while (sqlca.sqlcode == 0) 

{ 

EXEC SQL FETCH c_collection INTO :value; 

if (sqlca.sqlcode != 0) break; 

printf("\tItem %d, value = %d\n", ++item, value); 

} 

EXEC SQL CLOSE c_collection; 

EXEC SQL FREE c_collection;

mint main(int argc, char **argv) 

{ 


client collection list (integer not null) lc1; 

client collection set (integer not null) sc1; 

client collection multiset (integer not null) mc1; 

char *dbase = "stores_demo"; 

mint seq; 

char *stmt1 = 

"INSERT INTO t_collections VALUES(0, " 

"'LIST{-1,0,-2,3,0,0,32767,249}', 'SET{-1,0,-2,3}', " 

"'MULTISET{-1,0,0,-2,3,0}') "; 


if (argc > 1) 

dbase = argv[1]; 

EXEC SQL WHENEVER ERROR STOP; 

printf("Connect to %s\n", dbase); 

EXEC SQL connect to :dbase; 

EXEC SQL CREATE TEMP TABLE t_collections 

( 

seq serial not null, 

l1 list (integer not null), 

s1 set (integer not null), 

m1 multiset(integer not null) 

); 

EXEC SQL EXECUTE IMMEDIATE :stmt1; 

EXEC SQL ALLOCATE COLLECTION :lc1; 

EXEC SQL ALLOCATE COLLECTION :mc1; 

EXEC SQL ALLOCATE COLLECTION :sc1; 

} 

EXEC SQL DECLARE c_collect CURSOR FOR 

SELECT seq, l1, s1, m1 FROM t_collections; 

EXEC SQL OPEN c_collect; 

EXEC SQL FETCH c_collect INTO :seq, :lc1, :sc1, :mc1; 

EXEC SQL CLOSE c_collect; 

EXEC SQL FREE c_collect; 

print_collection("list/integer", lc1); 

print_collection("set/integer", sc1); 

print_collection("multiset/integer", mc1); 

EXEC SQL DEALLOCATE COLLECTION :lc1; 

EXEC SQL DEALLOCATE COLLECTION :mc1; 

EXEC SQL DEALLOCATE COLLECTION :sc1; 

puts("OK"); 

return 0; 


Example 4-12 shows the output of Example 4-11 on page 146. 

Example 4-12 Collection example output 

Connect to stores_demo 

COLLECTION: list/integer 

Item 1, value = -1 

Item 2, value = 0 







COLLECTION: set/integer 





COLLECTION: multiset/integer 







OK 

4.4.5 Exception handling 

The applications that you write require that the database server processes your 

SQL statements successfully as you intend. If a query fails and you do not know 

about the failure, you might display meaningless data to the user. 

To handle such errors, an Informix ESQL/C program must check that every SQL 

statement executes as you intend. 

This section discusses the two widely used exception handling methods in 

Informix applications development: 

► Use the SQLSTATE variable and the GET DIAGNOSTICS statement to check 

for runtime errors and warnings that your Informix ESQL/C program might 

generate. 

► Use the SQLCODE variable and the SQL Communications Area (sqlca) to 

check for runtime errors and warnings that your Informix ESQL/C program 

might generate. 


For more information about ESQL/C Exception handling, refer to: 


esqlc.doc/sii-11-40709.htm 

Exception handling with the SQLSTATE variable 

After the database server executes an SQL statement, it sets the SQLSTATE 

variable with a value that indicates the success or failure of the statement. From 

this value, your program can determine if it needs to perform further diagnostics. 

If the SQLSTATE variable indicates a problem, you can use the GET 

DIAGNOSTICS statement to obtain more information. 

Example 4-13 shows how to handle exceptions using the SQLSTATE variable 

and the GET DIAGNOSTICS statement. The GET DIAGNOSTICS statement 

returns information that is held in the fields of the diagnostics area. The 

diagnostics area is an internal structure that the database server updates after it 

executes an SQL statement. Each application has one diagnostics area. 

Example 4-13 Error handling in ESQL/C 

#include 

#include 

void error_chk() 

{ 


mint excp_count; 

char overflow[2]; 

mint excp_num=1; 

char message[255]; 

mint mlen; 

char sql_state_code[6]; 

mint i=1; 


printf("SQLSTATE: %s\n",SQLSTATE); 

printf("SQLCODE: %d\n", SQLCODE); 

printf("\n"); 

EXEC SQL get diagnostics :excp_count = NUMBER, :overflow = MORE; 

EXEC SQL get diagnostics exception :i :sql_state_code = RETURNED_SQLSTATE, :message = 

MESSAGE_TEXT, :mlen = MESSAGE_LENGTH; 

printf("EXCEPTION %d: SQLSTATE=%s\n", i, sql_state_code); 

message[mlen-1] = '\0'; 

printf("MESSAGE TEXT: %s\n", message); 

} 

mint main(int argc, char **argv) 

{ 


char *dbase = "stores_demo"; 


} 



if (argc > 1) 

dbase = argv[1]; 

EXEC SQL WHENEVER sqlerror CALL error_chk ; 

printf("Connect to %s\n", dbase); 

EXEC SQL connect to :dbase; 

EXEC SQL SELECT province FROM customer WHERE customer_num=1; 

return 0; 

OUTPUT: 

Connect to stores_demo 

SQLSTATE: IX000 

SQLCODE: -217 


EXCEPTION 1: SQLSTATE=IX000 

MESSAGE TEXT: Column (province) not found in any table in the query (or SLV is 

undefined). 

In this section, we list frequent ESQL/C errors and discuss how to diagnose a 

problem using the trace facility. The following typical errors can occur in ESQL/C 

applications: 

► Locale mismatch 

The most common error you might encounter when writing ESQL/C 

application is a locale mismatch error: 

-23197 Database locale information mismatch 

The straight forward solution is to match all the locale-related environment 

variables, namely CLIENT_LOCALE, DB_LOCALE, and SERVER_LOCALE. 

The default values for CLIENT_LOCALE are en_us.8859-1 for UNIX and 

en_us.1252 for Windows systems. You can set these variables using the 

export (ksh) or setenv (csh) commands, depending on which shell you are 

using. On Windows systems, you can set the locale using the setnet32.exe 

utility. 

For more information about these locales and related material, refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/index.jsp?topic=/com. 

ibm.glsug.doc/ids_gug_035.htm

► Compile and linking errors 

If there is a problem with the compile or linking, the following error message is 

returned: 

error while loading shared libraries: libifsql.so: cannot open shared 

object file: No such file or directory 

This error is due generally to a wrong setting of the shared library path. Refer 

to 4.4.1, “Creating an ESQL/C application” on page 128 for information about 

the correct settings. 

► Database connection errors 

if there is an issue with the database connection, the following error message 

is returned: 

-25596 The INFORMIXSERVER value is not listed in the sqlhosts file or the 

Registry. 

This error is due to incorrect setting of INFORMIXSERVER variable. Verify 

that it is set to the server instance to which you want to connect. 

The SQLIDEBUG trace 

ESQL/C uses the SQLI protocol to communicate with the Informix database 

server. The SQLIDEBUG trace allows you to trace all the messages between the 

client and server. You can use it to diagnose problems such as SQL errors, 

unexpected return values, or performance issues. 

You can enable the SQLIDEBUG trace on both the client and the server side. 

On the server side, you can enable SQLIDEBUG using the onmode -p 1 

sqli_dbg parameter. 

To set SQLIDEBUG on the client side, create the environment variable 

SQLIDEBUG with the following format: 

sqlidebug=2:path_trace_file 

where path_trace_file corresponds to the location and name of the trace file. 

Example 4-14 shows how to create the variable on a UNIX platform and how to 

decode the SQLI trace file using the sqliprint utility, which is included as part of 

Client SDK. 

Example 4-14 The SQLIDEBUG trace 

informix@irk:/work$ export SQLIDEBUG=2:/tmp/sqlitrace 

informix@irk:/work$ 

informix@irk:/work$ sqliprint /tmp/sqlitrace_17008_0_8c819d0 | more 

... 


C->S (16) Time: 2010-07-06 20:21:58.05185 

SQ_DBOPEN 

"stores7" [7] 

NOT EXCLUSIVE 

SQ_EOT 

S->C (28) Time: 2010-07-06 20:21:58.05487 

SQ_DONE 

Warning..: 0x15 

# rows...: 0 

rowid....: 0 

serial id: 0 

SQ_COST 

estimated #rows: 1 

estimated I/O..: 1 

SQ_EOT 

C->S (56) Time: 2010-07-06 20:21:58.05595 

SQ_PREPARE 

# values: 1 

CMD.....: "SELECT code, sname FROM state WHERE code = ?" [44] 

SQ_NDESCRIBE 

SQ_WANTDONE 

... 


Chapter 5. Working with the JDBC 

drivers 

5 

In this chapter, we describe how to develop a Java application using the two 

available Java Database Connectivity (JDBC) drivers. This chapter includes the 

following topics: 

► JDBC drivers for an Informix database 


► JDBC type mapping 

► Performing database operations 

► Informix additional features 


5.1 JDBC drivers for an Informix database 

Java Database Connectivity (JDBC) is the JavaSoft specification of a standard 

application programming interface (API) that allows Java programs to access 

database management systems. 

The JDBC API consists of a set of interfaces and classes written in the Java 

programming language. Using these standard interfaces and classes, 

programmers can write applications that connect to databases, send queries 

written in structured query language (SQL), and process the results. 

Because JDBC is a standard specification, one Java program that uses the 

JDBC API can connect to any database management system (DBMS), as long 

as a driver exists for that particular DBMS. 

For more information about the JDBC API, refer to JDBC documentation at 

http://java.sun.com/javase/6/docs/technotes/guides/jdbc/ 

You can use the following JDBC drivers from a Java application to process data 

in an IBM Informix database: 

► IBM Informix JDBC Driver 


Both JDBC drivers are developed as pure-Java drivers (Type 4). Thus, when you 

use a Type 4 driver from a Java application, your session connects directly to the 

database or database server without a middle layer. 

5.1.1 IBM Informix JDBC Driver 

IBM Informix JDBC Driver is a platform-independent, industry-standard Type 4 

driver that provides enhanced support for distributed transactions. 

Informix JDBC Driver follows the JDBC 3.0 specifications, providing support for 

the following IBM Informix database engines: 

► IBM Informix 7.x, 9.4x, 10.0, 11.10 and 11.50 

► IBM Informix Extended Parallel Server (XPS) 8.5x 

► IBM Informix Standard Engine (SE) 7.x 

► IBM Informix OnLine Version 5.x 

To use IBM Informix JDBC Driver Version 3.50.JC6, you must use a JDK 1.4.2 or 

later package on your platform. 


You can download the Informix JDBC Driver from: 

http://www14.software.ibm.com/webapp/download/search.jsp?go=y&rs=ifxjdbc 

Example 5-1 shows the contents of the Informix JDBC Driver package. 

Example 5-1 Informix JDBC directory 

demo 

doc 

javadoc 

release 

lib 

ifxjdbc.jar 

ifxjdbcx.jar 

ifxlang.jar 

ifxlsupp.jar 

ifxsqlj.jar 

ifxtools.jar 

license 

proxy 

This is a brief explanation of the .jar files in the driver: 

► ifxjdbc.jar 

The optimized implementations of the JDBC API interfaces, classes, and 

methods. 

► ifxjdbcx.jar 

The implementation of data source, connection pooling, and XA-related class 

files. 

► ifxlang.jar 

The localized versions of all message text supported by the driver. 

► ifxlsupp.jar 

Support functions for the ifxlang.jar package. 

► ifxsqlj.jar 

The classes for runtime support of SQLJ programs. 

► ifxtools.jar 

The ClassGenerator, lightweight directory access protocol (LDAP) loader, and 

other utilities. 

Chapter 5. Working with the JDBC drivers 155

5.1.2 IBM Data Server Driver for JDBC and SQLJ 

IBM Data Server Driver for JDBC and SQLJ, formerly known as IBM Driver for 

JDBC and SQLJ, is a JDBC driver that uses the DRDA protocol to communicate 

with IBM database servers. The use of a common communication protocol such 

as DRDA means that the IBM Data Server Driver for JDBC and SQLJ allows you 

to write client applications that can use both DB2 and Informix database servers. 

The IBM Data Server Driver for JDBC and SQLJ is compliant with the JDBC 3.0 

and JDBC 4.0 specifications. This driver is included as part of the IBM Data 

Server Driver Package, which is bundled with Informix Client Software 

Development Kit (Client SDK). IBM Data Server Driver for JDBC and SQLJ is 

also available as a separate download at: 

http://www-01.ibm.com/support/docview.wss?rs=71&uid=swg24026929 

Example 5-2 shows a listing of the files that are included in the IBM Data Server 

Driver for JDBC and SQLJ installation package and highlights important files. 

Example 5-2 Data Server Driver for JDBC directory (snippet) 

db2jcc.jar 

db2jcc4.jar 

sqlj.zip 

sqlj4.zip 

jdbc4_LI_en 

jdbc4_LI_en.rtf 

jdbc_LI_en 

The Data Server Driver for JDBC and SQLJ includes the following JDBC drivers: 

► db2jcc.jar 

Use the db2jcc.jar file in the CLASSPATH if you plan to use the version of 

the IBM Data Server Driver for JDBC and SQLJ that includes only JDBC 3.0 

and earlier functions. 

► db2jcc4.jar 

Use the db2jcc4.jar file in the CLASSPATH if you plan to use the version of 

the IBM Data Server Driver for JDBC and SQLJ that includes only JDBC 4.0 

and earlier functions. 

► sqlj.zip 

Provides support for SQLJ Java applications. SQLJ is used to embed SQL 

statements inside Java applications. 

► sqlj4.zip 

Type 4 driver for SQLJ applications. 



5.2.1 Configuration 

In this section, we discuss the setup and configuration parameters of Informix 

JDBC drivers. We also discuss how to verify the connection with the Informix 


The Data Server Client Driver for JDBC requires the use of a DRDA connection. 

Thus, the Informix database server must have an alias configured for DRDA 

communications. Informix JDBC Driver uses native Informix protocol or SQLI and 

requires no specific alias on the Informix database server when using the 

Informix JDBC Driver. 

On the database server, verify that the sqlhosts file contains the correct listeners 

for the Informix database server. 

Example 5-3 shows the sqlhosts file of the Informix server that we used in our 

examples. 

Example 5-3 Our sqlhosts file 

demo_on onipcshm kefka demo_on 

demo_on_tcp onsoctcp kefka 9088 

demo_on_drda drsoctcp kefka 9089 

For information regarding how to set up and configure a DRDA alias on the 

Informix server, refer to 2.1.3, “Configuring Informix Server” on page 27. 

On the client system, you must have one of the two JDBC drivers installed. For 

information about the installation and configuration, refer to 2.2.3, “Setting up 

IBM Data Server drivers” on page 43 and 2.2.4, “Setting up Informix JDBC” on 

page 53. 

To use any JDBC driver in an application, you must set the CLASSPATH 

environment variable to point to the driver files. The CLASSPATH environment 

variable tells the Java virtual machine (JVM) and other applications where to find 

the Java class libraries that are used in a Java program. 


Example 5-4 shows the CLASSPATH environment variable, which contains the 

default location of both JDBC drivers. 

Example 5-4 CLASSPATH example 

set CLASSPATH=C:\Program Files\IBM\IBM DATA SERVER 

DRIVER\java\db2jcc.jar;C:\Program 

Files\IBM\Informix_JDBC_Driver\lib\ifxjdbc.jar;C:\Program 

Files\IBM\Informix_JDBC_Driver\lib\ifxjdbcx.jar;%CLASSPATH%;.; 

Products such as IBM Data Studio or IBM WebSphere® Application Server have 

specific location and configuration files for the JDBC drivers. Always refer to each 

individual documentation for setup details. 

You can find additional information regarding the configuration of the 

CLASSPATH environment variable in refer to 2.2.3, “Setting up IBM Data Server 

drivers” on page 43 and 2.2.4, “Setting up Informix JDBC” on page 53. 

5.2.2 Verify connectivity with Informix JDBC Driver 

In this section, we demonstrate how to verify a correct setup and configuration of 

the Informix JDBC Driver. 

To load IBM Informix JDBC Driver, the application can use the following 

Class.forName() Java method, passing the name of the Informix JDBC Driver as 

argument: 

Class.forName("com.informix.jdbc.IfxDriver"); 

Example 5-5 contains a basic Java program that can be used to verify the 

connectivity with the Informix JDBC Driver. The connection string uses the 

following parameters: 

► The IBM Informix JDBC Driver identifier, jdbc:informix-sqli 

► The database server host name, kefka.lenexa.ibm.com 

You can also specify the IP address. 

► The port number of the SQLI listener of the Informix server, 9088 

► The database name, stores_demo 

► Informix instance identified by the INFORMIXSERVER variable 

► User and password for connecting to the database server 


Example 5-5 SimpleConnection.java 

import java.sql.*; 

public class SimpleConnection { 

public static void main(String[] args) { 

String url = 

"jdbc:informix-sqli://kefka.lenexa.ibm.com:9088/stores_demo:INFORMIXSERVER=demo 

_on;user=informix;password=Ifmx4you"; 

Connection conn = null; 

System.out.println("URL = \"" + url + "\""); 

try { 


} catch (Exception e) { 

System.out.println("FAILED: failed to load Informix JDBC driver."); 

} 

try { 

conn = DriverManager.getConnection(url); 

} catch (SQLException e) { 

System.out.println("FAILED: failed to connect!"); 

} 

try { 

System.out.println("Connected ..."); 

DatabaseMetaData md = conn.getMetaData(); 

System.out.println("Driver name: " + md.getDriverName()); 

System.out.println("Driver version: " + md.getDriverVersion()); 

System.out.println("Database product name: " 

+ md.getDatabaseProductName()); 

System.out.println("Database product version: " 

+ md.getDatabaseProductVersion()); 


System.out.println("FAILED: failed to connect!"); 

} 

try { 

conn.close(); 


System.out.println("FAILED: failed to close the connection!"); 

} 

System.out.println("Done!"); 

} 

} 


Example 5-6 shows the compile line and output of the SimpleConnect.java 

program. 

Example 5-6 Running SimpleConnection.java 

C:\RedBook>javac SimpleConnection.java 

C:\RedBook>java SimpleConnection 

URL = 

"jdbc:informix-sqli://kefka:9088/stores_demo:INFORMIXSERVER=demo_on;user=i 

nformix;password=Ifmx4you" 

Connected ... 

Driver name: IBM Informix JDBC Driver for IBM Informix Dynamic Server 

Driver version: 3.50.JC6W1 

Database product name: Informix Dynamic Server 

Database product version: 11.50.FC7 

Done! 

5.2.3 Verify connectivity with the Data Server Driver 

You can use the same Java program (Example 5-5 on page 159) to verify the 

connection with the Data Server Driver for JDBC with minor changes. The 

following changes are required: 

► Load the Data Server JDBC Driver class using the Class.forName() method: 

Class.forName("com.ibm.db2.jcc.DB2Driver"); 

► The name of the Data Server JDBC Driver in the connection string should be 

jdbc:ids. 

► The port number to use the Data Server Driver client is different from the 

Informix JDBC client. A common mistake is to specify the SQLI port in the 

URL that leads to an error such as the following error: 

com.ibm.db2.jcc.am.io: [jcc][t4][2030][11211][3.58.82] A communication 

error occurred during operations on the connection's underlying socket, 

socket input stream,or socket output stream. Error location: Reply.fill(). 

Message: Insufficient data. ERRORCODE=-4499, SQLSTATE=08001 

at com.ibm.db2.jcc.am.ed.a(ed.java:319) 

at com.ibm.db2.jcc.t4.a.a(a.java:416) 


Example 5-7 shows the changes to the SimpleConnection.java source code. 

You do not need to specify the INFORMIXSERVER variable when using the IBM 

Data Server Driver for JDBC. 

Example 5-7 SimpleConnection.java with Data Server JDBC Driver 

... 


} catch (ClassNotFoundException cnfe) { 

System.out.println("No such class available."); 

return; 

} 

try { 

con = DriverManager 

.getConnection("jdbc:ids://kefka:9089/stores_demo", 

"informix", "Ifmx4you"); 

System.out.println("connected"); 

... 

Example 5-8 shows how to compile and run the program. Notice that the 

metadata information that the JDBC driver retrieves is slightly different from the 

metadata retrieved with IBM Informix JDBC Driver. 

Example 5-8 Output of SimpleConnection.java using the Data Server JDBC Driver 

C:\RedBook>javac SimpleConnection.java 

C:\RedBook>java SimpleConnection 

connected 

Driver name: IBM DB2 JDBC Universal Driver Architecture 

Driver version: 3.58.82 

Database product name: IDS/UNIX64 

Database product version: IFX11500 

connected 

Done 

5.3 JDBC type mapping 

Mapping is a way of specifying data type equivalents. Because there are 

variations between the SQL data types that are supported by each database 

vendor, the JDBC API defines a set of generic SQL data types that to use on the 

Java application. In addition to these data types, which are defined by the JDBC 

driver, the Java language itself has its own data types that might differ from the 

SQL types that the database vendor uses. When writing a Java application, the 


programmer uses Java data types to manipulate the data. The application 

developers needs to understand the equivalent data type in JDBC and the 

equivalent data types on the database server. 

Table 5-1 lists a few of the data type mapping that is required when working with 

an IBM Informix database as examples. 

Table 5-1 Data Type Mapping from JDBC to Informix basic data types 

Java Type JDBC Type Informix Type 

long BIGINT INT8, BIGINT, BIGSERIAL 

byte[] BINARY, VARBINARY BYTE 

boolean BIT BOOLEAN 

java.sql.Date DATE DATE 

java.math.BigDecimal DECIMAL DECIMAL 

byte[] LONGVARBINARY BYTE or BLOB 

java.lang.String LONGVARCHAR TEXT or CLOB 

java.math.BigDecimal NUMERIC MONEY 

float, java.lang.Float REAL SMALLFLOAT 

java.sql.Time TIME DATETIME HOUR TO 

SECOND 

java.sql.Timestamp TIMESTAMP DATETIME YEAR TO 

FRACTION(5) 

For the complete list of data type mappings between the Informix SQL data types 

and the Informix JDBC Driver, refer to the JDBC Driver Programmer’s Guide at: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.jdbc_pg.doc 

/sii-xc-21122.htm#sii-xc-21122 

For more information regarding the data types that the IBM Data Server Driver for 

JDBC and SQLJ use, refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.jccids.doc/ 

com.ibm.db2.luw.apdv.java.doc/doc/rjvjdata.htm 


5.4 Performing database operations 

In this section, we provide examples of how to use IBM Informix JDBC Driver and 

IBM Data Server Driver for JDBC for typical database operations, such as 

connection to the Informix database, and to manipulate data. 

5.4.1 Connection to the database 

A Java application can obtain a connection with an Informix database using one 

of the following methods: 

► Use the DriverManager class. This method involves loading the JDBC driver 

using the Class.forName() method and obtaining a connection by calling the 

getConnection() method: 


con = DriverManager.getConnection("jdbc:ids://..."); 

► Use a DataSource object through the javax.sql extensions. 

DB2ConnectionPoolDataSource ds = new DB2ConnectionPoolDataSource(); 

PooledConnection poolconn = ds.getPooledConnection(); 

con = poolconn.getConnection(); 

The DriverManager class was implemented in the original JDBC 1.0 API. This 

class provides direct access to all the JDBC driver features; however, it requires 

the application to load the JDBC driver manually and to use a hard-coded 

connection string with the connection details. 

The DataSource interface was introduced in the JDBC 2.0 API as the preferred 

method to obtain a JDBC connection. The application has no need to load a 

JDBC driver class or provide hard-coded connection details. The interface needs 

to know only the name of the DataSource object that it wants to use. The details 

for the database connection are stored within the DataSource object definition 

outside the application code. 

Connecting using the DriverManager 

When using the DriverManager class to connect to an IBM Informix database, a 

connection string must be passed to the getConnection() method with the 

details for the database server. These details include information such as the 

system where the database server is running and the port number needed for the 

connection. 


Example 5-9 shows the syntax of the connection string used with Informix JDBC 

Driver and IBM Data Server Driver for JDBC. 

Example 5-9 DriverManager connection string syntax 

jdbc:[jdbc-driver]://[{ip-address|host-name}:{port-number|service-name}][/dbnam 

e]:INFORMIXSERVER=servername[{;user=user;password=password] 

Connecting to an Informix database uses the following parameters: 

► jdbc-driver 

This parameter identifies a particular JDBC driver. Informix JDBC Driver uses 

informix-sqli. IBM Data Server Driver for JDBC uses ids or db2. 

► ip-address or host-name 

This parameter specifies the system that is running the database server. 

► port-number|service-name 

This parameter specifies the communication port that the database server 

uses. 

► dbname 

This parameter names the database to open after a successful connection 

with the server. 

► INFORMIXSERVER 

This parameter identifies the name of the Informix database server to which 

to connect. This parameter is not required when using Data Server JDBC 

Driver. 

► User and password 

These parameters provide the authentication credentials for the connection. 

In addition to these standard details, which are common to all JDBC drivers, the 

connection string is also used to specify properties that are relevant only to a 

specific JDBC driver or database server. Table 5-2 lists some of the properties 

specific to Informix JDBC Driver. 

Table 5-2 Informix JDBC Driver connection string 


DB_LOCALE Locale of the database in the database server. 

CLIENT_LOCALE Locale used by the Client application 

INFORMIXCONTIME Time-out value for a connection with the server 

SQLIDEBUG Enable the trace of the SQLI protocol 



STMT_CACHE Enables SQL statement cache on the server 

IFX_ISOLATION_LEVEL Specify the default Isolation Level for the session 

IBM Data Server Driver for JDBC supports most of the Informix JDBC Driver 

properties. For a complete list of the properties that are supported when 

connecting to an Informix database server, refer to: 


jdbc_pg.doc/sii-02conect-66368.htm 

Example 5-10 shows how to compile a basic Java code that connects to the 

Informix database. The driver name and connection string are passed as 

parameters for the program. 

Example 5-10 A connect.java file 

C:\work>set CLASSPATH=ifxjdbc.jar:db2jcc.jar:. 

C:\work>type connect.java 


public class connect{ 

public static void main( String [] args ) { 


Statement is = null; 

if (args.lengthjavac connect.java 

C:\work>java connect "com.informix.jdbc.IfxDriver" 

"jdbc:informix-sqli://kodiak:9088/stores_demo:INFORMIXSERVER=demo_on; 


" 

Connected to Informix Dynamic Server 

C:\work>java connect "com.ibm.db2.jcc.DB2Driver" 

"jdbc:ids://kodiak:9089/stores_demo:user=informix;password=password"; 

Connected to IDS/NT64 

C:\work> 

Connecting using the DataSource object extensions 

When using a DataSource object, the information for the database connection is 

stored as properties of the DataSource object. These properties are usually 

stored in a Java Naming and Directory Interface (JNDI) service that is managed 

by the Java runtime or the application server. 

The application requires no knowledge about the specific connection details. It 

makes use of the DataSource object to get a connection with the database 

server. 

In addition to the method implemented by the JDBC driver to set standard 

properties, both Informix JDBC Driver and Data Server Driver for JDBC provide 

extra methods to set and retrieve properties that are specific to the Informix 

database. These properties have the same effect on the database session as the 

Informix environment variables that are used by other Informix APIs, such as 

ODBC or .NET. 

Example 5-11 shows a DataSource object that is created using the Informix 

JDBC Driver and how to set some of the DataSource object properties. 

Example 5-11 DataSource object sample 

IfxDataSource ds = new IfxDataSource(); 

ds.setServerName("demo_on"); 

ds.setDatabaseName("stores_demo"); 

ds.setPortNumber(9089); 

ds.setIfxIFXHOST("kodiak"); 

ds.setIfxCLIENT_LOCALE("en_US.CP1252"); 

ds.getConnection("informix", "password"); 


You can use these Informix specific properties to modify the behavior of the 

JDBC driver or to control particular features of the database server. Table 5-3 

lists a portion of the DataSource object properties that are implemented in the 

Informix JDBC Driver. 

Table 5-3 DataSource object properties 

Informix variable Method 

CLIENT_LOCALE public String getIfxCLIENT_LOCALE() 

public void setIfxCLIENT_LOCALE() 

DB_LOCALE public String getIfxDB_LOCALE() 

public void setIfxDB_LOCALE() 

IFX_ISOLATION_LEVEL public String getIfxIFX_ISOLATION_LEVEL() 

public void setIfxIFX_ISOLATION_LEVEL (l) 

IFX_LOCK_MODE_WAIT public int getIfxIFX_LOCK_MODE_WAIT() 

public void setIfxIFX_LOCK_MODE_WAIT () 

SQLIDEBUG public String getIfxSQLIDEBUG () 

public void setIfxSQLIDEBUG () 

STMT_CACHE public String getIfxSTMT_CACHE() 

public void setIfxSTMT_CACHE() 

USEV5SERVER public boolean isIfxUSEV5SERVER() 

public void setIfxUSEV5SERVER() 

For a complete list of all the available properties, refer to: 


jdbc_pg.doc/sii-xb-13590.htm 

Because IBM Data Server Driver for JDBC supports both Informix and DB2 

database servers, the DataSource object properties that it provides are different 

from those provided by Informix JDBC Driver. For a complete list, refer to: 


jccids.doc/com.ibm.db2.luw.apdv.java.doc/doc/rjvdsprp.htm 


5.4.2 Manipulating data 

In this section, we provide basic examples of how to perform typical data 

manipulation tasks using a JDBC driver with an IBM Informix database. 


A Java application can use a Statement object to run basic SQL statements 

against the database server. The Statement interface provides two methods: 

► executeQuery() returns a ResultSet value 

Use this method to run SQL statements that return data (for example, a 

SELECT SQL statement). 

► executeUpdate() returns the number of rows effected by the SQL statement 

Use this method to perform INSERT, DELETE, and UPDATE operations or to 

run Data Definition Language (DDL) statements. 

Example 5-12 demonstrates how to perform a DELETE statement using the 

executeUpdate() method. 

Example 5-12 An executeUpdate sample 

C:\work>type delete.java 


public class delete{ 




try { 


conn = 

DriverManager.getConnection("jdbc:informix-sqli://kodiak:9088/stores_demo:INFOR 

MIXSERVER=demo_on"); 


is = conn.createStatement(); 

int rc=is.executeUpdate("DELETE FROM state WHERE code='"+args[0]+"'"); 

System.out.format("Deleted %d rows",rc); 

conn.close(); 

} 

catch ( Exception e ) { 

System.err.println(e); 

} 

}

} 

C:\work> 

C:\work>java delete AZ 

Deleted 1 rows 

C:\work> 

Prepare SQL statement with parameters 

You can use the PreparedStatement object to run the prepared SQL statement 

against the database server. Use the PreparedStatement object when the 

application uses an SQL statement repeatedly. The application can run the SQL 

statement multiple times with different values, which saves the time that the 

application takes to process and optimize an SQL statement. 

Example 5-13 demonstrates how to use a PreparedStatement object. The 

example inserts a row in the state table using the parameters that are supplied 

through the command line. 

Example 5-13 An insert.java sample 

C:\work>cat insert.java 


import java.util.*; 

import java.text.*; 

public class insert{ 



try { 


conn = 



PreparedStatement pstmt=conn.prepareStatement("INSERT INTO state 

VALUES(?,?,?)"); 

pstmt.setString(1, args[0]); 



int rc=pstmt.executeUpdate(); 

System.out.format("Inserted %d rows",rc); 


conn.close(); 

} 



} 

} 

} 

C:\work>java insert AZ Arizona 0 

Inserted 1 rows 

C:\work> 

Retrieve data from a database table 

To retrieve data from a database table or a function that returns more than one 

row, a JDBC application must use the ResultSet object. When the 

executeQuery() method from the Statement or PreparedStatement object is call, 

the data is returned in the form of a ResultSet object. This object allows the 

fetching of rows from the database. 

Example 5-14 demonstrates how to run an SQL SELECT statement to retrieve 

data using the PreparedStatement and ResultSet objects. The result of the 

prepare statement is stored in the ResultSet object, dbRes. After that, the 

dbRes.next() method is used to scroll through the ResultSet data. 

Example 5-14 A select.java sample 

C:\work>cat select.java 


public class select { 



ResultSet dbRes = null; 


try { 


conn = 


MIXSERVER=demo_on;’); 

PreparedStatement pstmt=conn.prepareStatement("SELECT * FROM state where 

code

dbRes = pstmt.getResultSet(); 

while (dbRes.next()) { 

System.out.format("%s,",dbRes.getString(1)); 

System.out.format("%s,",dbRes.getString(2)); 

System.out.format("%f\n",dbRes.getDouble(3)); 

} 

dbRes.close(); 

conn.close(); 

} 



} 

} 

} 

C:\work>java select CA 

AL,Alabama ,0.040000 

AR,Arizona ,0.000000 

AZ,Arizona ,0.055000 

C:\work> 

Transactions 

Local transaction are controlled directly with the connection object. Methods 

such as Connection.commit() and Connection.rollback() are used to resolved 

a transaction. 

By default, all the connections that are created by the Informix JDBC Driver 

Connection object are in AutoCommit mode. Thus, every SQL statement sent to 

the Informix database server is committed automatically. If control over the 

transaction is required, you can turn off the AutoCommit mode using the 

Connection.setAutoCommit() method. 

When using Informix JDBC Driver in an XA environment (XA is a standard 

specification for distributed transactions), the AutoCommit feature is always 

disabled. The transaction manager is the only component that has control over 

the transaction. 


Example 5-15 demonstrates how to disable AutoCommit mode using the 

setAutoCommit(false) method. 

Example 5-15 A sample localtrans.java file 

C:\work>cat localtrans.java 



import java.text.*; 

public class localtrans{ 




try { 


conn = 



conn.setAutoCommit(false); 


is = conn.createStatement(); 

int rc = is.executeUpdate("DELETE FROM state WHERE code='UK'"); 

System.out.format("Deleted %d rows\n",rc); 

System.out.format("Aborting transaction\n"); 

conn.rollback(); 

conn.close(); 

} 


e.printStackTrace(); 

} 

} 

} 

C:\work>java localtrans 

Deleted 1 rows 

Aborting transaction 

C:\work>

Run a user-defined routine 

The CallableStatement object provides a way to run a user-defined routine 

(UDR) using a standard method that is common to all the IBM database servers. 

The results from the execution of a UDR is returned as a result set or as an OUT 

parameter. Use the following SQL syntax to call a UDR using the 

CallableStatement interface: 

"{? = call function_name (?, ?,...)}"; 

The placeholders identify the IN, OUT, and INOUT parameters for the UDR. 

The application can set and retrieve the value for the routine parameters using 

the registerOutParameter() and getxxx() methods. 

Example 5-16 shows a basic UDR that is defined with two OUT parameters. 

Example 5-16 A state_tax SQL routine 

CREATE FUNCTION state_tax(OUT vtax percent, 

vcode CHAR(2), 

OUT vsname CHAR(20)) 

RETURNS BOOLEAN; 

SELECT sales_tax,upper(sname) 

INTO vtax, vsname FROM state 

WHERE code=vcode; 

RETURN 't'; 

END FUNCTION; 

We use CallableStatement to invoke this UDR from a JDBC application. 

Example 5-17 demonstrates how to set the IN and OUT for the UDR. The 

BOOLEAN value is returned directly by the SQL function and retrieved using a 

ResultSet object. To retrieve the OUT parameters, the example uses the 

getDouble() and GetString() methods. 

Example 5-17 A callable.java sample file 

C:\work>cat callable.java 


public class callable { 



try { 



conn = 


MIXSERVER=demo_on;"); 

CallableStatement cstmt = conn.prepareCall ("{? = call state_tax(?, ?, 

?)}"); 

cstmt.registerOutParameter(1, Types.DOUBLE); 

cstmt.registerOutParameter(3, Types.CHAR); 

cstmt.setString(2, "CA"); 

ResultSet dbRes = cstmt.executeQuery(); 

// Retrieve OUT parameters from the function 

while (dbRes.next()) 

System.out.format("UDR returns = %s\n", dbRes.getBoolean(1)); 

// Retrieve OUT parameters from the function 

System.out.format("OUT tax %s\n",cstmt.getDouble(1)); 

System.out.format("OUT sname %s\n",cstmt.getString(3)); 


cstmt.close(); 

conn.close(); 

} 



} 

} 

} 

C:\work>java callable 

UDR returns = true 

OUT tax 0.0825 

OUT sname CALIFORNIA 

C:\work> 

5.5 Informix additional features 

This section demonstrates the use of the following additional IBM Informix 

features: 

► Batch inserts or updates and using ResultSet metadata 

► BIGSERIAL data type 

► Informix smart large objects 

► Secure Socket Layer 


5.5.1 Batch inserts or updates and using ResultSet metadata 

In this section, we demonstrate the following concepts: 

► Batch inserts 

When performing multiple inserts (or updates) using a prepared statement, it 

is more efficient to do all the inserts in bulk. The method adds all the inserts in 

a batch and then runs the batch. 

► Using ResultSet metadata 

When you run a query from a Java program that generates a result set, there 

is additional information available that is separate from the result set itself. 

This additional information about the data is returned by the ResultSet 

metadata. For example, you might use ResultSet metadata to obtain table 

definition information from one database to another database. You can 

dynamically obtain all the details about each column that returns data. 

Example 5-18 shows the batch insert and how to obtain the column name and 

column type from the ResultSet metadata. The schema for the gentemp table is 

as follows: 

CREATE TABLE gentemp (id INT, name VARCHAR(15) NOT NULL) 

We use the con.prepareStatement() method to prepare the SQL INSERT 

statement. Then, we execute the statement using the pstmt.addBatch() method, 

which makes the INSERT statement a part of a batch operation. After adding 10 

rows to the table, we execute the batch operation using the 

pstmt.executeBatch() method. 

The metadata information for the table is retrieved using the rs.getMetaData() 

method. 

Example 5-18 Listing for the IfxBatchDemo.java file 


import java.io.*; 

public class IfxBatchDemo { 

public static void main(String args[]) throws SQLException, IOException,Exception { 

String IfxURL = 

"jdbc:informix-sqli://kodiak:9088/stores_demo:INFORMIXSERVER=demo_on"; 

Connection con = null; 

int cnt = 0; 

System.out.println("Start"); 


con = DriverManager.getConnection(IfxURL); 


con.setAutoCommit(false); 

Statement stmt = null; 

PreparedStatement pstmt = null; 

ResultSet rs = null; 

ResultSetMetaData rsmd = null; 

pstmt = con.prepareStatement("INSERT INTO gentemp (id,name) VALUES (?,?)"); 

// Fill in 10 rows 

for (int i = 0; i < 10; i++) { 

pstmt.setInt(1, i + 1000); 

pstmt.setString(2, "String #" + i); 

pstmt.addBatch(); 

} 

int[] rows = pstmt.executeBatch(); 

System.out.println(" Inserted data. Rows = " + rows.length); 

con.commit(); 

pstmt.close(); 

pstmt = con.prepareStatement("SELECT * FROM gentemp"); 

rs = pstmt.executeQuery(); 

rsmd = rs.getMetaData(); 

System.out.println(" " + "Col Names " + rsmd.getColumnName(1) + "," 

+ rsmd.getColumnName(2)); 

System.out.println(" " + "Col Types " + rsmd.getColumnTypeName(1) 

+ "," + rsmd.getColumnTypeName(2)); 

int row = 1; 

while (rs.next()) { 

System.out.println(" Row " + row + " = " 

+ rs.getInt(rsmd.getColumnName(1)) + "," 

+ rs.getString(rsmd.getColumnName(2))); 

row++; 

} 

pstmt.close(); 

con.commit(); 

con.close(); 

} 

} 


5.5.2 BIGSERIAL data type 

IBM Informix version 11.50 implements the ANSI standard SQL data type 

BIGINT and the BIGSERIAL data types: 

► BIGINT is mapped to the JDBC standard BIGINT data type. It can be used 

from a Java application as any other Informix data type. 

► BIGSERIAL (similar to SERIAL and SERIAL8) does not have an obvious 

mapping to any JDBC data type. Thus, the application must use 

Informix-specific JDBC methods to retrieve the value of these columns. 

The methods to access Informix serial data types are included in the Informix 

JDBC implementation of the JAVA java.sql.Statement interface, IfxStatement. 

You can use the getSerial(), getSerial8(), and getBigSerial() methods to 

retrieve the last value that was inserted on a serial column. 

Example 5-19 shows how to retrieve a BIGSERIAL value using the 

IfxStatement.getBigSerial() method. The example uses the following schema 

for the table: 

CREATE TABLE tempbs(id BIGSERIAL, name CHAR(10)); 

Example 5-19 The bigserial.java sample 


import com.informix.jdbc.*; 

public class bigserial { 




long insertedserial = 0; 

String 

url="jdbc:informix-sqli://kodiak:9088/stores_demo:INFORMIXSERVER=demo_on;"; 

try { 


conn = DriverManager.getConnection(url); 

IfxStatement stmt= (IfxStatement) conn.createStatement(); 

stmt.executeUpdate("INSERT INTO tempbs VALUES (0,'test');"); 

insertedserial =stmt.getBigSerial(); 

System.out.println("Last serial: \t"+insertedserial); 

stmt.executeQuery("SELECT FIRST 1 * FROM tempbs ORDER BY rowid DESC"); 

dbRes = stmt.getResultSet(); 

while (dbRes.next()) { 


System.out.format("Last row: \t%d,",dbRes.getLong(1)); 

System.out.format("%s\n",dbRes.getString(2)); 

} 


conn.close(); 

} 



} 

} 

} 

Example 5-19 on page 177 inserts a row in the tempbs table and stores the last 

BIGSERIAL value in the insertedSerial variable. Example 5-20 shows how to 

compile the example and its output. 

Example 5-20 The output of the bigserial.java file 

C:\work>javac bigserial.java 

C:\work>java bigserial 

Last serial: 14 

Last row: 14,test 

C:\work> 

5.5.3 Informix smart large objects 

Smart large objects are a type of large object that Informix supports. Smart large 

objects are stored logically in a table column but stored physically in a specific 

type of dbspace called smart blob space. 

The data that is stored in the table column is a structure that contains information 

about the large object, such as special attributes or pointers to the location in the 

smart blob space that contains the data. Informix has the following types of smart 

large objects: 

► A BLOB stores binary data. 

► A CLOB stores character data. 


You can manipulate smart large objects with the Informix JDBC Driver using the 

following methods: 

► Standard JDBC 3.0 API 

Using standard JDBC methods such as getString(), setAsciiStream(), or 

getBinaryStream() allows an application to handle smart lager objects as 

standard Java data types. 

► Informix smart-large-object extensions 

If an application requires random access to the large data, it must use 

Informix smart-large-object extensions. These extensions to the JDBC API 

give the application greater control over the smart-large-object data in terms 

of object properties, concurrency access, and logging. 

The IfxSmartBlob interface implements most of the smart-large-object 

extensions, methods such as IfxLoCreate(), IfxLoOpen(), IfxLoRead(), and 

IfxLoWrite() can be used to access the smart large object structures and to 

manipulate the data of the object. 

For a complete description of all the Informix smart-large-objects extensions, 

refer to the JDBC Driver Programmer’s Guide, which is available at: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/index.jsp?topic=/com. 

ibm.jdbc_pg.doc/sii-04data-36421.htm 

Note: IBM Data Server Driver for JDBC does not support the Informix smart 

large object extensions. Only the standard JDBC API is available to work with 

smart large objects. 

Using the standard JDBC API 

Working with smart large objects using the JDBC API does not require any 

specific Java code. Example 5-21 demonstrates how to retrieve a CLOB column 

from the Informix database using the getString() method. 

Example 5-21 The getclob.java sample 

C:\work>cat getclob.java 


public class getclob { 





try { 


conn = DriverManager.getConnection( 

"jdbc:informix-sqli://kodiak:9088/stores_demo:INFORMIXSERVER=demo_on;"); 


PreparedStatement pstmt=conn.prepareStatement("SELECT * FROM catalog WHERE 

catalog_num=?"); 


pstmt.executeQuery(); 

dbRes = pstmt.getResultSet(); 

dbRes.next(); 

System.out.println("Advert description: "+dbRes.getString("advert_descr")); 


conn.close(); 

} 



} 

} 

} 

C:\work>javac getclob.java 

C:\work>java getclob 10001 

Advert description: Brown leather. Specify first baseman's or infield/outfield 

style. Specify right- or left-handed. 

C:\work> 

Using the Informix extensions 

The smart-large-object extensions allows a Java application to have direct 

control over the large object structures and data pointers that are used to 

describe the large object. 

The following interfaces provide the methods that are needed to handle smart 

large objects: 

► IfxLobDescriptor stores the internal characteristics for a smart large object. 

The application must create an IfxLobDescriptor object to insert a new large 

object in the database. 

► IfxLocator identifies a particular large object. An IfxLocator object can be 

created or retrieved from the database to perform any I/O operations with the 

large object. 

► IfxSmartBlob represents a smart large object within the Informix JDBC 

Driver. This object provides all the methods that are necessary to create, 

open, read, and write to a large object. 

► IfxloStat stores statistical information about a smart large object, such as 

the size, last access time, last modified time, and last status change. 

► IfxBblob and IfxCblob add extended functionality to the standard JDBC 3.0 

BLOB and CLOB classes. 


Example 5-22 demonstrates how to read data from a smart large object using the 

IfxSmartBlob method. The code performs the following steps to select the CLOB 

column advert_descr: 

1. Stores the advert_descr column as an IfxCblob object using the getClob() 

method. 

2. Gets the IfxLocator from the IfxCblob object through the 

cblob.getLocator() method. 

3. Creates an IfxSmartBlob object and uses the IfxLocator to open the smart 

large object in smb.IfxLoOpen(). 

4. Reads the first 200 bytes of the CLOB using the smb.IfxLoRead() method. 

5. Closes the large object and releases the IfxLocator. 

Example 5-22 The loext.java file 


import com.informix.jdbc.*; 

public class loext{ 



byte[] buffer = new byte[200]; 

try { 


conn = DriverManager.getConnection( 

"jdbc:informix-sqli://kodiak:9088/stores_demo:INFORMIXSERVER=demo_on;"); 

PreparedStatement pstmt=conn.prepareStatement("SELECT * FROM catalog WHERE 

catalog_num=?"); 


pstmt.executeQuery(); 

ResultSet dbRes = pstmt.getResultSet(); 

dbRes.next(); 

IfxCblob cblob = (IfxCblob) dbRes.getClob("advert_descr"); 

IfxLocator loPtr = cblob.getLocator(); 

IfxSmartBlob smb = new IfxSmartBlob(conn); 

int loFd = smb.IfxLoOpen(loPtr, smb.LO_RDONLY); 

int bytesReaded = smb.IfxLoRead(loFd, buffer, buffer.length); 

smb.IfxLoClose(loFd); 

smb.IfxLoRelease(loPtr); 

System.out.println("Advert description: "+new String(buffer).trim()); 


conn.close(); 

} 




} 

} 

} 

Example 5-23 shows how to compile the loext.java sample and the output of 

this sample. 

Example 5-23 The output of the loext.java file 

C:\work>javac loext.java 

C:\work>java loext 10001 

Advert description: Brown leather. Specify first baseman's or infield/outfield 


C:\work> 

For more information regarding the use of smart large objects with Informix 

JDBC Driver, refer to the JDBC Driver Programer’s Guide, which is available at: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.jdbc_pg.doc 

/sii-04data-36421.htm#sii-04data-36421 

5.5.4 Secure Socket Layer 

In addition to the encrypted communications that are provided by the 

Communication Support Module (CSM), the Informix database server supports 

the use of Secure Socket Layer (SSL) communications for the encryption of the 

packages between client and server. 

Informix JDBC Driver supports only CSM encryptions. You must use IBM Data 

Server Driver for JDBC to connect to an SSL-enabled Informix database server. 

Before you can use SSL encryption with an Informix database, you must 

configure both server and client systems. 


Preparing the Informix server for SSL 

To enable SSL on the Informix server, create an Informix alias using the drsocssl 

protocol. 

Example 5-24 enables SSL communications with an Informix server. 

Example 5-24 SSL configuration on the Informix server 

$gsk7capicmd -keydb -create -db kodiak.kdb -pw password -type cms -stash 

$gsk7capicmd -cert -create -db kodiak.kdb -pw password -label testlabel -dn 

"CN=bedfont.uk.ibm.com,O=ibm,C=UK" -size 1024 -default_cert yes 

$gsk7capicmd -cert -extract -db kodiak.kdb -format ascii -label testlabel -pw 

password -target testlabel.cert 

$ pwd 

/usr3/11.50/ssl 

$ ls -a 

. kodiak.crl kodiak.rdb testlabel.cert 

.. kodiak.kdb kodiak.sth 

$ onstat -c | grep ssl 

DBSERVERALIASES kodiak_shm,kodiak_drda,kodiak_ssl 

$ grep kodiak_ssl $INFORMIXSQLHOSTS 

kodiak_ssl drsocssl kodiak 9191 

$ 

For detailed information regarding the configuration of SSL with an Informix 

server, refer to the Configuring a Server Instance for Secure Sockets Layer 

Connections topic in the information center at: 


sec.doc/ids_ssl_002.htm 

Preparing client for SSL 

To enable SSL encryption, both the client and server systems must use the same 

certificated file. You can import a certified file into the client system using the 

keytool utility, which is included with the Java SDK framework. 

Example 5-25 demonstrates how to import the testlabel.cert certificate file 

that was created in Example 5-24 on page 183 to enable a trusted relationship 

between client and server. A keystore file is created to store the keys for the SSL 

encrypted connection. 

Example 5-25 SSL Client side configuration 

C:\work>keytool -importcert -file testlabel.cert -keystore .keystore 

Enter keystore password: 

Re-enter new password: 

Owner: CN=bedfont.uk.ibm.com, O=ibm, C=UK 


Issuer: CN=bedfont.uk.ibm.com, O=ibm, C=UK 

Serial number: -14b0e6b89751eab1 

Valid from: Thu Jul 15 08:10:31 PDT 2010 until: Sat Jul 16 08:10:31 PDT 2011 

Certificate fingerprints: 

MD5: 66:FA:CF:44:9F:F3:38:40:7B:9D:93:D6:D6:1C:DB:C5 

SHA1: CF:38:6F:CA:C9:A1:54:43:FC:64:AD:F6:DF:5F:CA:65:01:58:DE:DE 

Signature algorithm name: SHA1withRSA 

Version: 3 

Trust this certificate? [no]: yes 

Certificate was added to keystore 

C:\work>dir .key* /b 

.keystore 

C:\work> 

Using a Java client 

A Java application can connect to the SSL Informix server by performing the 

following operations: 

► Set the javax.net.ssl.truststore system property to point to the created 

keystore (in our example, C:\work\.keystore). 

► Set the javax.net.ssl.trustStorePassword System property to the 

password that is used for the certificate. 

► Get a data source object. 

► Set the port number to the SSL port, 9191. 

► Set the data source property setSslConnection to true. 

Example 5-26 shows basic Java code that connects to an SSL Informix server. 

Example 5-26 Listing conssl.java 


import javax.sql.*; 



import com.ibm.db2.jcc.*; 

public class conssl { 

public static void main(String args[]) throws SQLException, IOException, 

Exception { 

System.setProperty ("javax.net.ssl.trustStore","c:/work/.keystore"); 

System.setProperty ("javax.net.ssl.trustStorePassword","password"); 

DB2ConnectionPoolDataSource ds = new DB2ConnectionPoolDataSource(); 

ds.setUser("informix"); 


} 

} 

ds.setPassword("password"); 

ds.setServerName("kodiak"); 

ds.setDatabaseName("stores_demo"); 

ds.setPortNumber(9191); 

ds.setDriverType(4); 

ds.setSslConnection(true); // SSL 

PooledConnection poolconn = ds.getPooledConnection(); 

Connection con = poolconn.getConnection(); 

DatabaseMetaData md = con.getMetaData(); 

System.out.println("Driver name: " + md.getDriverName()); 

System.out.println("Connected to "+ md.getDatabaseProductName()); 

System.out.println("Database product version: " + 

md.getDatabaseProductVersion()); 

con.close(); 

After a successful connection, the code produces metadata information such as 

the driver name and database version. Example 5-27 shows the output. 

Example 5-27 Output of conssl.java 

C:\work>javac conssl.java 

C:\work>java conssl 

Driver name: IBM DB2 JDBC Universal Driver Architecture 

Connected to IDS/UNIX32 

Database product version: IFX11500 

C:\work> 

5.6 Typical errors 

Common issues in Java applications for Informix include errors due to an 

application development environment without proper configuration and SQL 

syntax errors. In this section, we discuss these typical errors. 


5.6.1 Class not found errors 

The following code shows a class not found error message: 

C:\RedBook>java IfxSimpleConnection 

Exception in thread "main" java.lang.NoClassDefFoundError: 

IfxSimpleConnection 

Caused by: java.lang.ClassNotFoundException: IfxSimpleConnection 

... 

This type of error is usually from either failing to load the JDBC driver or failing to 

load the application class because the environment is not configured properly. 

To resolve this problem: 

► Make sure that you have the JDBC driver .jar files in your CLASSPATH. 

► Make sure that you have a “.” (dot) to include your current directory in the 

CLASSPATH. 

5.6.2 Connectivity errors 

When an application fails to connect to the server, you see an error message that 

is similar to the following message: 

Exception in thread "main" java.sql.SQLException: 

com.informix.asf.IfxASFException: Attempt to connect to database server 

(demo_on) failed. 

at com.informix.jdbc.IfxSqliConnect.(IfxSqliConnect.java:1319) 

... 

To resolve this problem: 

► Verify that the server is running and that the ports are configured correctly on 

the server. 

► Check the port number specified in the application. Remember, Informix 

JDBC Driver connects to an SQLI port, and IBM Data Server driver connects 

to a DRDA port. 

► Verify that there is no firewall between the client and server. Use Telnet to 

connect from the client to the server. 


5.6.3 Syntax errors 

5.7 Tracing 

The exception with SQLCODE -201 is a syntax error in an SQL statement that 

you are trying to run. Other than examining the SQL manually, it can be helpful to 

know the location of the SQL about which the server is complaining by obtaining 

the SQL statement offset as follows: 

try { 

stmt.execute( SQL ); 

} 

catch(Exception e) { 

System.out.println ("Error Offset :"+((IfmxConnection 

conn).getSQLStatementOffset() ); 

System.out.println(e.getMessage() ); 

} 

Tracing the communication with the Informix database server might be required 

for further diagnostics. The method that you use to enable tracing depends on 

the Informix JDBC Driver that you are using. 

5.7.1 IBM Informix JDBC Driver 

Informix JDBC uses the Informix SQLI protocol for the communication with the 

database server. A trace file with all the SQLI messages can be generated by 

enabling the SQLITRACE feature within the JDBC driver. 

Depending on the method used for the connection, the SQLIDEBUG can be 

activated using a connection string keyword or a DataSource method: 

► Set trace for Informix JDBC Driver using DriverManager 

DriverManager.getConnection("jdbc:informix-sqli://kodiak:9088/sysmaster:INF 

ORMIXSERVER=demo_on;user=;password=;SQLIDEBUG=/tmp/jdbctrace"); 

► Set trace for Informix JDBC Driver using a DataSource object 

IfxDataSource ifxds = new IfxDataSource(); 

ifxds.setIfxSQLIDEBUG("c:/temp/sqli.trc"); 

You can run the trace through the sqliprint utility to render it to text form. 


5.7.2 IBM Data Server Driver for JDBC 

IBM Data Server Driver for JDBC uses DRDA as the network protocol and 

produces a DRDA trace, which is a straight text output trace that can be 

examined directly. 

You can enable DRDA trace with the JDBC using the following methods: 

► Set trace for IBM Data Server Driver using DriverManager 

DriverManager.getConnection("jdbc:ids://kodiak:9089/sysmaster:user=;passwor 

d=;traceFile=/jcc.trc;TraceLevel=TRACE_ALL;"); 

► Set trace for IBM Data Server Driver using a DataSource object 

DB2SimpleDataSource ds = new DB2SimpleDataSource(); 

ds.setTraceFile("/jcc.trc"); 

ds.setTraceLevel(com.ibm.db2.jcc.DB2BaseDataSource.TRACE_ALL); 

ds.setTraceFileAppend(false); 

Both SQLIDEBUG and DRDADEBUG traces can be activated at the server side 

rather than on the client system using the Informix onmode utility that is included 

with the Informix database server. You can find more information about both 

traces in “Tracing” on page 117. 


Chapter 6. IBM Informix with Hibernate 

This chapter describes how to use the HIbernate Java package with an IBM 

Informix database. 

It includes the following topics: 

► Hibernate for Java 


► Using Hibernate with an Informix database 

6 


6.1 Hibernate for Java 

This section describes the concepts of Hibernate and the Java Persistence API 

(JPA) programming model. 

6.1.1 Overview of Hibernate 

Hibernate is an open source Java object-relational mapping (ORM) and 

persistence framework that allows you to map Plain Old Java Objects (POJO) to 

relational database tables using XML configuration files. Hibernate also provides 

a data query language, Hibernate Query Language (HQL), and retrieval facilities 

that help reduce development time spent on manual data handling in JDBC calls 

or SQL statements. 

Persistence data refers to any data that must be stored in the database and that 

must exist after the application has stopped running. Hibernate provides a way to 

persist the typical relational data as well as Java objects that the application 

uses. 

A relational database stores the information in a tabular way with tables and 

columns. A relational database ensures the integrity of the data using SQL 

objects such as constraints and referential integrity. 

An object-orientated programming (OOP) language, such as Java or C++, does 

not have the same data representation as relational databases. The data is 

represented by objects with attributes and methods. The relationship between 

these objects is implemented with concepts such as inheritance or polymorphism 

that do not exist in a relational database. 

ORM technologies such as Hibernate try to solve the limitations of 

object-orientated languages when using relational databases. ORM allows 

developers to focus on the business logic of the application, without the need for 

dealing with the data access layer. A developer needs to load only the customer 

object and does not need to care about how the information for that particular 

customer is stored in the database. ORM solutions produce more robust and 

portable code, which means faster development time. 

For more information about Hibernate, refer to: 

http://docs.jboss.org/hibernate/stable/core/reference/en/html/ 


6.1.2 Hibernate concepts 

The Hibernate framework includes the following basic concepts: 

► Persistence, in Hibernate terms, refers to the concept of storing the state of a 

Java object in the database so that it can be restored later. 

► Mapping is the process to map SQL tables to Java objects. Mapping is 

accomplished using XML mapping files or using Java annotations (metadata 

that is added to the application source) in the Java code. 

► Object processing refers to the use of the mapped objects from the 

application code. How to save and load the state of an Java object using the 

Hibernate API or the specific Hibernate Query Language (HQL). 

In a simplified words, Hibernate for Java is a set of Java APIs that allows you to 

store and retrieve the state of Java objects into a database using a JDBC driver. 

Figure 6-1 illustrates the typical components of a Hibernate application. 

Figure 6-1 Hibernate components 

Chapter 6. IBM Informix with Hibernate 191

A Hibernate application includes the following components (as shown in 

Figure 6-1): 

► Application represents the Java application. 

► Java object is the object that the application wants to persist (keep in the 

database). 

► Hibernate properties is the configuration file for the Hibernate framework, 

named hibernate.cfg.xml, that contains information such as the connection 

details for the database server or the SQL dialect to use. 

► XML Mapping is an XML file that contains the mappings between Java 

objects and database objects. 

► JDBC is the JDBC driver that is used for the database connection. You can 

use both IBM Informix JDBC Driver and IBM Data Server Driver for JDBC with 

Hibernate. 

► Informix database is the IBM Informix database server. 

In addition to the ORM, Hibernate also provides connection management and a 

transaction management services to be used with a Java application. We do not 

discuss these topics in this section. For information regarding the use and 

configuration of the connection and transaction management services, refer to: 

http://docs.jboss.org/hibernate/core/3.3/reference/en/html/transactions.html 


6.2.1 Installation 

This section describes the installation and configuration of Hibernate to be used 

with an IBM Informix database. 

Hibernate is an open source project that you can download from: 

http://sourceforge.net/projects/hibernate/files 

The latest version of Hibernate API is V3.5.3, which fully implements the JPA 2.0. 

The compressed package name is 

hibernate-distribution-3.5.3-Final-dist.zip. 


Example 6-1 shows the contents of the Hibernate compressed package. 

Example 6-1 Hibernate distribution content 

changelog.txt 

documentation 

javadocs 

manual 

hibernate-testing.jar 

hibernate3.jar 

hibernate_logo.gif 

lgpl.txt 

lib 

bytecode 

jpa 

hibernate-jpa-2.0-api-1.0.0.Final.jar 

optional 

c3p0 

ehcache 

infinispan 

jbosscache 

oscache 

proxool 

swarmcache 

required 

antlr-2.7.6.jar 

commons-collections-3.1.jar 

dom4j-1.6.1.jar 

javassist-3.9.0.GA.jar 

jta-1.1.jar 

slf4j-api-1.5.8.jar 

project 

The package contains most of the Java libraries that are required to run a 

Hibernate application, including the Hibernate documentation and the source 

code project files for the Hibernate libraries. Table 6-1 describes the Java 

libraries that are included. 

Table 6-1 Included Java libraries 

File Description 

hibernate3.jar Hibernate Core library for Relational Persistence 

hibernate-jpa-2.0-api-1 

.0.0.Final.jar 

Hibernate definition of the Java Persistence 2.0 API 

antlr-2.7.6.jar Framework for grammatical descriptions containing Java 



File Description 

commons-collections-3.1 

.jar 

dom4j-1.6.1.jar XML framework for Java 

In addition to the libraries that are supplied by the Hibernate package, the .jar 

packages contain the following libraries for the JDBC driver that must be included 

in the CLASSPATH: 

► ifxjdbc.jar: IBM Informix JDBC Driver 

► db2jcc.jar: IBM Data Server Driver for JDBC 

The Hibernate package is also available as a Maven 2 artifact. Maven is an open 

source software project management that uses XML files based on the Project 

Object Model (POM) to manage all the attributes and dependencies files of a 

Java project. For more information about Maven, refer to the Apache Maven 

Project documentation at: 

http://maven.apache.org/what-is-maven.html 

In this section, we discuss the configuration settings that are required to develop 

an Informix application with Hibernate. 


Types that extend and augment the Java Collections 

Framework 

javassist-3.9.0.GA.jar Java programming Assistant 

jta-1.1.jar The javax.transaction package 

slf4j-api-1.5.8.jar API for the Simple Logging Facade for Java (SLF4J) 

Note: The slf4j-api-1.5.8.jar package does not contain the complete set 

of libraries for the Simple Logging Facade for Java (SLF4J). You must use a 

package that provides an implementation for SLF4J in conjunction with 

Hibernate API. 

Several implementations of SLF4J are available at: 

http://www.slf4j.org/download.html 

In our examples, we use slf4j-simple-1.6.1.jar and slf4j-nop-1.6.1.jar, 

which provide simple-logging and discarded-logging.

CLASSPATH 

CLASSPATH is an environment variable that tells the Java compiler and the Java 

virtual machine (JVM) where to look for Java class files and Java libraries. 

To use Hibernate with a Java program, you must include the core library, the 

hibernate3.jar file, and all the libraries in the lib/required directory in the 

application CLASSPATH. An implementation of the SLF4J logger and the JDBC 

driver is also required for Hibernate to work. 

Example 6-2 shows a UNIX script that creates the CLASSPATH environment 

variable. We use slf4j-nop-1.6.1.jar with discarded-logging and the Informix 

JDBC Driver ifxjdbc.jar file for our examples. 

Example 6-2 Hibernate CLASSPATH script 

export CLASSPATH=$CLASSPATH:. 

export CLASSPATH=$CLASSPATH:/work/lib/commons-collections-3.1.jar 

export CLASSPATH=$CLASSPATH:/work/lib/dom4j-1.6.1.jar 

export CLASSPATH=$CLASSPATH:/work/lib/hibernate-jpa-2.0-api-1.0.0.Final.jar 

export CLASSPATH=$CLASSPATH:/work/lib/hibernate3.jar 

export CLASSPATH=$CLASSPATH:/work/lib/javassist-3.9.0.GA.jar 

export CLASSPATH=$CLASSPATH:/work/lib/jta-1.1.jar 

export CLASSPATH=$CLASSPATH:/work/lib/slf4j-api-1.6.1.jar 

export CLASSPATH=$CLASSPATH:/work/lib/antlr-2.7.6.jar 

export CLASSPATH=$CLASSPATH:/work/lib/slf4j-nop-1.6.1.jar 

export CLASSPATH=$CLASSPATH:/work/lib/ifxjdbc.jar 

Hibernate configuration file 

Hibernate provides the following files to specify configuration parameters: 

► hibernate.properties: A standard Java properties text file 

► hibernate.cfg.xml: An XML formatted file 

Both files contain the same configuration details for the Hibernate service. If both 

files exist, the XML configuration file overrides the settings in the properties file. 

The configuration file (hibernate.propertieshibernate.cfg.xml) contains the 

information that Hibernate needs to connect to the database server. Details such 

as name of the JDBC driver class, ConnectionString, and authentication details 

are kept in this file. 

The Hibernate libraries require the configuration file (hibernate.properties or 

hibernate.cfg.xml) to be located in the root directory of the CLASSPATH. 


Example 6-3 shows a hibernate.cfg.xml file using the Informix JDBC Driver. 

Example 6-3 A hibernate.cfg.xml sample 

 

 

 

 

 

 

com.informix.jdbc.IfxDriver 

 

 

jdbc:informix-sqli://kodiak:9088/stores_demo:INFORMIXSERVER=demo_on; 

 

 

informix 

 

 

password 

 

 

org.hibernate.dialect.InformixDialect 

 

false 

update 

 

 

 

 

In addition to the JDBC information, the configuration file also contains 

configuration details for the Hibernate service. 

Use the dialect property to specify the SQL dialect for the database server. A 

Hibernate dialect is a Java class that contains specific details regarding the SQL 

syntax that is needed to communicate with a particular database. 

When using the IBM Informix JDBC Driver with Hibernate, set the dialect to 

orb.hibernate.dialect.InformixDialect. The dialect for the IBM Data Server 

Driver for JDBC is org.hibernate.dialect.DB2Dialect. 

These classes are included in the hibernate3.jar package and contain a basic, 

non-optimized implementation of the Informix dialect. 


Note: You can find a patch that adds Informix SQL optimizations to the original 

Hibernate dialect for Informix databases at: 

http://www.iiug.org/opensource/files/hibernate-3.3.2_informix.tar.gz 

The XML configuration file allows the inclusion of XML mapping files. Use the 

mapping resource property to specify the XML file that contains the mapping 

between the SQL table and the Java object. 

Example 6-3 on page 196 includes the State.hbm.xml mapping file as part of the 

hibernate configuration, as shown in the following line: 

 

Properties, such as hibernate.show_sql or hbm2ddl.auto, control the behavior 

of the Hibernate service. Use the hibernate.show_sql property to dump all the 

SQL statements to the console, which might be useful for debugging purposes. 

Set the hbm2ddl.auto property to update to specify that the schema for the SQL 

table is updated automatically if it differs from the definition in the XML definition. 

For more information regarding all the supported properties for the Hibernate 

configuration files, refer to: 

http://docs.jboss.org/hibernate/core/3.3/reference/en/html/session-configuration 

.html 

XML mapping file 

You can use the XML mapping file to specify the relations between a Java object 

and an SQL database object. These mapping definitions are used to provide 

Hibernate with the information that is needed to persist the Java objects into the 

relational database. They also provide support features, such as creating the 

database schema and relationship between the objects. 

XML mapping files are not required when using Java annotations. The mapping 

information is added using annotations in the Java source code. 

Example 6-4 shows a basic XML file used to map the States table to the State 

Java object. 

Example 6-4 The State.hbm.xml file 

 

 

 

name="State" 

table="States"> 

 

 

 

 

 

 

 

The definition includes information, such as the table name and column to be 

used as identifier (ID), and specific attributes for the elements, such as the 

generator class that defines a column as an identifier that is generated 

automatically by the Java libraries. These details are used by the Hibernate 

libraries to generate SQL statements automatically, including Data Definition 

Language (DDL) and Data Manipulation Language (DML). 

For a complete list of all the attributes that are available in an XML mapping file, 

refer to: 

http://docs.jboss.org/hibernate/core/3.3/reference/en/html/mapping.html#mapping 

-declaration 

6.3 Using Hibernate with an Informix database 

In this section, we demonstrate how to perform basic operations using the 

Hibernate API with an IBM Informix database server. 

6.3.1 Components of a Hibernate application 

To develop a Hibernate application, you need to complete the following tasks: 

► Create the Java objects. 

► Create the XML Mapping files for the Java objects. 

► Create the configuration file for the Hibernate framework. 


► Create the HibernateUtil helper class that provides access to the Hibernate 

session. 

► Create the application that will use the Java persistence objects. 

Java object 

Hibernate supports the use of Plain Old Java Objects (POJO) for the definition of 

a persistence object. Thus, there is a special requirement when writing the Java 

class that represents the object. 

Example 6-5 shows the contents of the State.java file that is used to define the 

State object. The State Java object is created as any normal Java object. The 

object has three properties (id, code, and sname) and the usual methods to set 

and get those properties, such as setcode() or setsname(). The id attribute is 

used to uniquely identify the Java persistence object. 

Example 6-5 The State.java file 

public class State { 

private Long id; 

private String code; 

private String sname; 

} 

public State() {} 

public State(String text, String text2) { 

this.code = text; 

this.sname = text2; 

} 

public Long getId() { 

return id; 

} 

private void setId(Long id) { 

this.id = id; 

} 

public String getcode() { 

return code; 

} 

public void setcode(String text) { 


} 

public String getsname() { 

return sname; 

} 

public void setsname(String text) { 

this.sname = text; 

} 


Example 6-6 shows the CLASSPATH variable used in the environment and how 

to compile the State.java source code. 

Example 6-6 Compile line for State.java 

C:\work>set classpath 

CLASSPATH=C:\work\lib\commons-collections-3.1.jar;C:\work\lib\dom4j-1.6.1.jar;C 

:\work\lib\hibernate-jpa-2.0-api-1.0.0.Final.jar;C:\work\lib\hibernate3.jar;C:\ 

work\lib\ifxjdbc.jar;C:\work\lib\javassist-3.9.0.GA.jar;C:\work\lib\jta-1.1.jar 

;C:\work\lib\slf4j-api-1.6.1.jar;C:\work\lib\slf4j-nop-1.6.1.jar;C:\work\lib\an 

tlr-2.7.6.jar;. 

C:\work>javac State.java 

C:\work> 

XML mapping file 

An XML mapping file is required to link the Java object with an Informix database 

object. The States table keeps all the instances of the Java State object. 

The common convention for the name of the XML mapping file is 

objectname_hbm.xml. 

Example 6-7 shows the contents of the State_hbm.xml file. 

Example 6-7 The State_hbm.xml file 

 

 

 

 

 

 

 

 

 

 

 


The name of the class is State. It is mapped to the Informix SQL table States. 

The State class contains two types of elements: 

► 

Defines the mapping from that property to the primary key column. It usually 

contains the generator element that is used to generate unique identifiers for 

the ID property. 

The generator class supports different methods of generating identifiers. 

Increment is the most basic method, and sequence allows to use an SQL 

sequence to obtain the identifier value. For a list of all the methods 

implemented in the generator interface, refer to: 

http://docs.jboss.org/hibernate/core/3.3/reference/en/html/mapping.html#map 

ping-declaration-id 

► 

Defines a property for the object, including the name of the property and the 

name of the mapped database table column. 

The elements of the XML mapping file can have additional attributes to define 

specific characteristics of the columns it maps. You can use attributes such as 

type and not-null to specify the data type and the nullability of a column. 

Hibernate configuration file 

The Hibernate configuration file must reside in the root directory of the 

CLASSPATH. It contains configuration values for the Hibernate service and 

connection details for the database server. 

Example 6-8 shows the contents of the hibernate.cfg.xml file that we used in 

our sample. The connection details correspond to the IBM Informix JDBC Driver. 

Example 6-8 The hibernate.cfg.xml file 

 

 

 

 

 

 

com.informix.jdbc.IfxDriver 

 

 

jdbc:informix-sqli://kodiak:9088/stores_demo:INFORMIXSERVER=demo_on; 

 

 


informix 

 

 

password 

 

 

org.hibernate.dialect.InformixDialect 

 

false 

update 

 

 

 

Example 6-9 shows the attributes that are required for an IBM Data Server Driver 

for JDBC connection. The configuration file includes the State.hbm.xml XML 

mapping for the State object. 

Example 6-9 IBM Data Server Driver hibernate.cfg.xml file 

 

org.hibernate.dialect.DB2Dialect 

 

 

com.ibm.db2.jcc.DB2Driver 

 

 

jdbc:ids://kodiak:9089/stores_demo; 

 

HibernateUtil helper class 

The HibernateUtil class is used to interact with the Hibernate service. It 

performs the operations related to the Hibernate SessionFactory classes that 

provide a convenient way for the application to access the Hibernate session. 

The Java file that contains the HibernateUtil helper class is 

HibernateUtil.java. Example 6-10 shows a typical helper class. 

Example 6-10 The HiberanteUtil.java file 

import org.hibernate.SessionFactory; 

import org.hibernate.cfg.Configuration; 

public class HibernateUtil { 

private static final SessionFactory sessionFactory; 


static { 

try { 

// Creates the SessionFactory from hibernate.cfg.xml 

sessionFactory = new Configuration().configure().buildSessionFactory(); 

} 

catch (Throwable ex) { 

System.err.println("SessionFactory creation failed." + ex); 

throw new ExceptionInInitializerError(ex); 

} 

} 

public static SessionFactory getSessionFactory() { 

return sessionFactory; 

} 

public static void shutdown() { 

// Close caches and connection pools 

getSessionFactory().close(); 

} 

} 

This class creates a Hibernate session using the parameters that are specified in 

the Hibernate configuration file. Create the class by compiling the 

HibernateUtil.java Java file as follows: 

javac HibernateUtil.java 

Java application 

The only task that is required by a Java application to use the Hibernate 

persistence object is to create a Hibernate Session instance using the 

HibernateUtil helper class. After that, the application can create persist objects 

in the same manner that it does for any other Java object. 

6.3.2 Working with a Hibernate object 

Developers must follow an object-orientated methodology when writing 

applications using the Hibernate API. With Hibernate, the data is represented by 

the status and properties of an object, not by tables and rows in a relational 

database. 

Storing 

When a persistent object is created and saved or stored, an insert operation is 

performed on the database. 


Example 6-11 shows basic Java code that creates a new State object using the 

parameters that are supplied in the command line. The example creates a 

Hibernate Session object using the helper class and then creates a new State 

object called myState. The myState.setcode() and myState.setsname() methods 

are used to stored the values that are passed from the command line. 

Example 6-11 The Create.java code 


import org.hibernate.*; 

import javax.persistence.*; 

public class create { 


Session Session = HibernateUtil.getSessionFactory().openSession(); 

Transaction Transaction = Session.beginTransaction(); 

State myState = new State(); 

myState.setcode(args[0]); 

myState.setsname(args[1]); 

Long stateId = (Long) Session.save(myState); 

System.out.println("Stated added: "+myState.getcode()+", " 

+myState.getsname()); 

Transaction.commit(); 

Session.close(); 

// Shutting down the application 

HibernateUtil.shutdown(); 

} 

} 

Example 6-12 shows the compile line and the output of the create.java sample. 

Example 6-12 Compiling the create.java sample and the output 

C:\work>javac create.java 

C:\work>java create AZ Arizona 

Stated added: AZ, Arizona 

C:\work> 

The hbm2ddl.auto Hibernate property is set to update in the configuration file, 

which means that if the table does not exist in the database, it is created 

automatically using the table model that is defined in the XML mapping file. 


Example 6-13 shows the schema of the created States table and the new row 

that is added to the table. 

Example 6-13 States table schema 

D:\Infx\ids1150>dbaccess stores_demo - 

Database selected. 

> INFO COLUMNS FOR states; 

Column name Type Nulls 

id int8 no 

code varchar(255) yes 

sname varchar(255) yes 

> SELECT * FROM states; 

id 1 

code AZ 

sname Arizona 

1 row(s) retrieved. 

> 

The Java object is made persistent, thus saving the state of the object in the 

database, using the Session.save() Hibernate method and committing the unit 

of work with Transaction.commit(). 

Loading 

To retrieve a persistent object from the database server, the application must 

create a Hibernate session and load the state of the object into the current 

session. 

The process of loading a persistence object can be achieved using several 

methods: 

► Use Session.load() and Session.get() to retrieve the state of an object from 

the database using the object identifier as reference. For example, to load the 

State object with ID equal to 1, the following code is needed: 

State mystateobj = (State) Session.load(State.class,1); 


The only difference between the load() and get() methods is the returned 

value. If the object is not found, get() returns a null and load() throws an 

exception. 

► Use an SQL or HQL query. HQL is similar to SQL but is optimized for an 

object-orientated environment. You can use methods, such as 

Session.createQuery() and Session.createCiteria(), to load the state of 

one or multiple objects from the database server. The following command 

loads all State objects into a list: 

List states = session.createQuery("from state").list(); 

Example 6-14 demonstrates how to load a single object from the database using 

the Session.load() method. 

Example 6-14 The load.java sample 

import java.util.List; 

import org.hibernate.HibernateException; 

import org.hibernate.Session; 

import org.hibernate.Transaction; 

import org.hibernate.criterion.*; 

public class load { 


} 

} 

Long stateId = null; 



stateId=Long.parseLong(args[0]); 

State mystate = (State) Session.load(State.class,stateId); 

System.out.println(mystate.getcode() +", " + 

mystate.getsname() ); 




Example 6-15 shows how to compile and run the previous example. The 

application loads the State object identified by the id value passed through the 

command line. 

Example 6-15 Output of the load.java sample 

C:\work>javac load.java 

C:\work>java load 1 

AZ, Arizona 

C:\work>java load 2 

CA, California 

C:\work> 

The application can use an HQL query to load all the objects, or entities, of a 

particular type. All the State objects are kept in the States table. Example 6-16 

shows how to retrieve a list of the State entities. 

Example 6-16 The list.java sample 

C:\work>cat list.java 




public class list { 


Session newSession = HibernateUtil.getSessionFactory().openSession(); 

Transaction newTransaction = newSession.beginTransaction(); 

List states = newSession.createQuery("from State order by id asc").list(); 

for ( Iterator iter = states.iterator(); 

iter.hasNext(); ) { 

State state = (State) iter.next(); 

System.out.println(state.getId() +", "+ state.getcode() 

+", " + state.getsname() ); 

} 

newTransaction.commit(); 

newSession.close(); 


} 

} 

C:\work>javac list.java 

C:\work>java list 


1, AZ, Arizona 

2, CA, California 

C:\work> 

Updating 

Updating an persistent object is the process of changing the state of the object. 

No specific operation is required for this task. The application must load the 

object, change the object properties, and save it. 

Example 6-17 demonstrates how to update individual objects. It uses the 

parameters from the command line to change the code and sname properties of a 

State object. 

Example 6-17 The update.java sample 

C:\work>cat update.java 





public class update { 







mystate.setcode(args[1]); 

mystate.setsname(args[2]); 

Session.save(mystate); 

System.out.println("new values: "+ mystate.getcode()+", "+ 




} 

} 

C:\work>javac update.java 


C:\work>java update 1 AZ ARIZONA 

new values: AZ, ARIZONA 

C:\work> 

Criteria 

Criteria queries are a feature of HQL that allow the building of complex queries 

using an object-orientated API. 

Example 6-18 shows how to update a president object using an HQL criteria to 

retrieve the object from the database. The HQL criteria is created using the name 

of the class for the object that you want to select, State.class. An HQL 

Restriction, Restriction.eq("code", args[0]), is used to specify a filter for the 

criteria. This restriction specifies that the query returns the objects with a specific 

code value. 

Example 6-18 The update2.java sample 




import org.hibernate.criterion.*; 

public class update2 { 




Criteria crit = Session.createCriteria(State.class); 

crit.add( Restrictions.eq( "code", args[0]) ); 

List states = crit.list(); 

for ( Iterator iter = states.iterator(); iter.hasNext(); ) { 

State mystate = (State) iter.next(); 

mystate.setsname(args[1]); 

Session.flush(); 

Long msgId = (Long) Session.save(mystate); 

System.out.println("new values: "+ mystate.getcode()+", "+ 


} 




} 

} 


Example 6-19 shows the output of the example. 

Example 6-19 The update2.java output 

C:\work>javac update2.java 

C:\work>java update2 AZ Arizona 

new values: AZ, Arizona 

C:\work> 

Deleting 

In the Hibernate framework, deleting a persistence object means to make the 

object transient. A transient object is a typical Java object, but the state of the 

object is not stored anywhere. Thus, the object exists only during the life of the 

application. 

An object can be deleted using the Session.delete() method. Example 6-20 

demonstrates how to use the Session.delete() method. 

Example 6-20 The delete.java sample 

C:\work>cat delete.java 





public class delete { 







Session.delete(mystate); 

System.out.println( "Object deleted"); 



} 

} 

C:\work>javac delete.java 


C:\work>java delete 2 

Object deleted 

C:\work>java list 

1, AZ, Arizona 

C:\work> 

One of the main features of using Hibernate is that it abstracts the JDBC layer 

from the application. Thus, applications written using the Hibernate API are not 

tied to a specific JDBC driver or relational database server. 

You can run all the examples that we present in this section using any of the two 

Informix JDBC drivers that are available, IBM Informix JDBC Driver or IBM Data 

Server Driver for JDBC. Refer to the “Hibernate configuration file” on page 195 

for information regarding how to switch between JDBC drivers. 

For more information about how to develop using the Hibernate API, refer to: 

http://docs.jboss.org/hibernate/core/3.3/reference/en/html/objectstate.html 

6.3.3 Using annotations 

Java annotations is a feature added into the Java 5 Software Development Kit 

(SDK) that allows the inclusion of special annotations within the Java source 

code to express metadata relating to program objects. 

Hibernate supports Java annotations through the use of the Hibernate 

Annotations Extensions. These extensions allow you to include the definition of 

specific Hibernate properties, such as configuration properties or object 

mappings properties, directly into the Java code. 

With annotations, there is no need for a specific XML mapping file to link the Java 

objects with the database objects. 

Example 6-21 shows the definition of the State object using Hibernate 

annotations. Annotations, such as @Entity, @Table or @Column, define the 

mapping information that is needed to persist the Java objects into the database. 

Example 6-21 The state.java sample with annotations 


@Entity 

@Table(name="States") 

public class State { 


private Long id; 

private String code; 

private String sname; 

public State() {} 

public State(String text, String text2) { 


this.sname = text2; 

} 

@Id 

@GeneratedValue(strategy=GenerationType.IDENTITY ) 

@Column(name="id") 

public Long getId() { 

return id; 

} 

private void setId(Long id) { 

this.id = id; 

} 

@Column(name="code", length=2, nullable=false) 

public String getcode() { 

return code; 

} 

public void setcode(String text) { 


} 

@Column(name="sname", length=15, nullable=false) 

public String getsname() { 

return sname; 

} 

public void setsname(String text) { 

this.sname = text; 

} 

} 

Because all the information that is required to map the objects is specified as 

annotations, you do not need to include a section in the Hibernate 

hibernate.cfg.xml configuration file. 


When using annotations, the HibernateUtil helper class, HibernateUtil.java, 

uses the AnnotationConfiguration() interface to retrieve the Hibernate 

properties and the metadata definition from the object class. Example 6-22 

shows the HibernateUtil.java file that is used to create a SessionFactory for 

the State.class object. 

Example 6-22 The HibernateUtil.java sample for annotations 

import org.hibernate.SessionFactory; 

import org.hibernate.cfg.AnnotationConfiguration; 

public class HibernateUtil { 

private static final SessionFactory sessionFactory; 

static { 

try { 

// Create the SessionFactory from hibernate.cfg.xml 

} 

sessionFactory = new AnnotationConfiguration() 

.configure() 

.addAnnotatedClass(State.class) 

.buildSessionFactory(); 

} catch (Throwable ex) { 

System.err.println("Initial SessionFactory creation failed." + ex); 

throw new ExceptionInInitializerError(ex); 

} 

} 

public static SessionFactory getSessionFactory() { 

return sessionFactory; 

} 

public static void shutdown() { 

getSessionFactory().close(); 

} 

You do not need to change the code for the Java applications that use the 

persistence object. The process when using Hibernate annotations for 

manipulating the objects is the same as when using the XML mapping files. 

You can find a description of all the Hibernate annotation extensions at: 

http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#en 

tity-hibspec 



Chapter 7. Working with IBM Informix 

OLE DB Provider 

7 

This chapter describes IBM Informix OLE DB Provider. It includes the following 

topics: 

► IBM Informix OLE DB Provider 


► Developing an OLE DB application 

► Visual Basic, ADO.NET, and SQL Server 

► Troubleshooting and tracing 


7.1 IBM Informix OLE DB Provider 

Informix OLE DB Provider is a Universal Data Access component that enables 

IBM Informix Server access from OLE DB consumers. 

Microsoft OLE DB is a specification for a set of interfaces that is designed to 

expose data from a variety of sources (relational and non-relational). OLE DB 

uses the Component Object Model (COM) to accomplish this. 

You can use IBM Informix OLE DB Provider to enable client applications, such as 

ActiveX Data Object (ADO) applications and web pages, to access data on an 

IBM Informix database server. 

Table 7-1 shows the name and COM class ID of the IBM Informix OLE DB 

Provider. 

Table 7-1 COM class ID 

Name DLL CLSID 

ifxoledbc iifxoledbc.dll {A6D00422-FD6C-11D0-8043-00A0C90F1C59} 

Table 7-2 lists the Informix database servers that support IBM Informix OLE DB 

Provider. 

Table 7-2 Supported databases 

Database Server Versions 

IBM Informix 10.0,11.10,11.50 




In this section, we discuss how to install and set up the OLE DB provider and 

how to perform basic connectivity tests. 

7.2.1 Installation and setup 

IBM Informix OLE DB Provider is included only in the Windows version of 

Informix Client Software Development Kit (Client SDK). The Informix OLE DB 


Provider is selected by default in the Client SDK installation. During the 

installation process, the provider is registered automatically on the Windows 

registry as a command component. 

The default installation directory is the C:\Program 

Files\IBM\Informix\Client-SDK directory. The INFORMIXDIR environment 

variable should point to the directory where the product is installed. The provider 

shared library, ifxoledbc.dll, is located in %INFORMIXDIR%\bin directory. 

Because by default Informix OLE DB Provider is registered during Client SDK 

installation, manual registration is usually not required. However, if needed, you 

can register Informix OLE DB Provider manually using the Microsoft 

regsvr32.exe tool using the following command: 

regsvr32.exe %INFORMIXDIR%\bin\ifxoledbc.dll 

Note: On a Windows x64 (64-bit) system, there are two versions of the 

regsvr32.exe tool: 

► The 32-bit version is located in C:\WINDOWS\SysWOW64 

► The 64-bit version is located in C:\WINDOWS\System 

Use the correct version when registering Informix OLE DB Provider. 

Otherwise, the application will fail to load the shared library due to a 

mismatched version. 

After installation, you must run the coledbp.sql script on the database server 

against the sysmaster database as user informix to add the tables and functions 

that are required by Informix OLE DB Provider to work. 

The coledbp.sql script is located in the %INFORMIXDIR%\etc directory. If you want 

to remove the support functions and tables, use the doledbp.sql script that is 

located in the same directory. 


Client SDK does not contain any specific tool to test Informix OLE DB Provider. 

Internally, Informix OLE DB Provider uses the same Informix connection libraries 

as ESQL/C or ODBC. You can test the basic connection details for your database 

server using the iLogin utility that is included in the %INFORMIXDIR%\bin directory. 

Testing using Visual Basic Scripting Edition 

Visual Basic Scripting Edition (VBScript) is a scripting language that is included 

as part of the Windows operating system. It provides access to ADO objects 

Chapter 7. Working with IBM Informix OLE DB Provider 217

through COM. You can use it to test whether the Informix OLE DB Provider is 

configured properly. 

A VBScript file is a text file with a .vbs extension that is loaded automatically and 

executed by Visual Basic at run time. 

Example 7-1 shows a simple VBScript that loads Informix OLE DB Provider and 

selects a single row from the database. 

Example 7-1 The connect.vbs script 

' ---- Test_Ifx.vbs ---- 

On Error Resume Next 

args = WScript.Arguments.Count 

If args < 1 then 

WScript.Echo "usage: connect.vbs Connection_string" 

WScript.Echo " e.g.: connect.vbs ""Data Source=stores_demo@demo_on;User 

ID=informix;Password=password;""" 

WScript.Quit 

end If 

set conn=createobject("ADODB.Connection") 

conn.provider = "Ifxoledbc" 

conn.connectionstring = WScript.Arguments.Item(0) 

conn.open 

If Err then 

WScript.Echo "Error!! "+conn.Errors(0).Description 

Else 

WScript.Echo "Connected" 

conn.close 

End If 

' ---- Test_Ifx.vbs ---- 

Example 7-2 shows how run the connect.vbs script with a data source string as 

the parameter to test the database connectivity. 

Example 7-2 Output of the connect.vbs script 

c:\work>connect.vbs 

usage: connect.vbs Connection_string 

e.g.: connect.vbs "Data Source=stores_demo@demo_on;User 

ID=informix;Password=password;" 

c:\work>connect.vbs "Data Source=stores_demo@demo_on;User 

ID=informix;Password=password;" 

Connected 


c:\work>connect.vbs "Data Source=stores_demo@demo_on;User 

ID=informix;Password=invalid;" 

Error!! EIX000: (-951) Incorrect password or user informix@dubito is not known 

on the database server. 

Rowset Viewer 

You can also test Informix OLE DB Provider using the Rowset Viewer. The 

Rowset Viewer is included with the Microsoft Data Access Components (MDAC) 

2.8 Software Development Kit (SDK), which you can download from the following 

location: 

http://www.microsoft.com/downloads/details.aspx?FamilyID=6c050fe3-c795-4b7d-b03 

7-185d0506396c 

To test Informix OLE DB Provider using the Rowset Viewer tool, perform the 

following steps: 

1. Run the Rowset tool. 

2. Select File � Full Connect. 

3. In the Full Connect dialog box, choose Ifxoledbc in the Provider field. 

4. In the DataSource field, enter the database server name to which you want to 

connect, for example stores_demo@demo_on. 

5. Click OK. 

You also can use Rowset Viewer to run SQL statements against the database 

server. To execute an SQL statement, write the SQL text in the Rowset pane and 

click . 

7.3 Developing an OLE DB application 

This section describes the interfaces that are implemented in Informix OLE DB 

Provider and demonstrates how to perform basic database operations. 

In this section, we discuss the following topics: 

► Supported interfaces 

► Connecting to database 

► Type mapping 

► Cursors 

► Typical database operations 


7.3.1 Supported interfaces 

An OLE DB application creates objects based on ADO interfaces to perform 

operations against a database server. Table 7-3 lists a few ADO interfaces that 

are implemented in Informix OLE DB Provider as examples. For a complete list, 

refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.oledb.doc/s 

ii-xa-21954.htm#sii-xa-21954 

Table 7-3 Informix OLE DB Provider supported interfaces 

Interface Description 

IAccessor Provides methods for accessor management 

IColumnsInfo Provides information about columns of a rowset or prepared 

command 

ICommand Executes commands 

IDBCreateCommand Obtains a new command 

IDBCreateSession Obtains a new session 

IDBDataSourceAdmin Creates, destroys, and modifies data source objects 

IDBProperties Gets and sets the values of properties on the data source 

object or enumerator and obtains information about all 

properties that are supported 

IErrorLookup Used by OLE DB error objects to determine the values of the 

error message, source, Help file path, and context ID based 

on the return code and a provider-specific error number 

IGetDataSource Obtains an interface pointer to the data source object 

IRowsetIdentity Indicates row instance identity is implemented on the rowset 

and enables testing for row identity 

ISessionProperties Returns information about the properties a session supports 

and the current settings of those properties 

ITransaction Used to commit, abort, and obtain status information about 

transactions 


7.3.2 Connecting to database 

In this section, we describe the connection string options with Informix OLE DB 

Provider. 

The connection details for the database server are passed to Informix OLE DB 

Provider using a connection string. If the Provider attribute of the Connection 

object is not set, you must include the provider keyword as part of the 

connection string to specify the name of Informix OLE DB Provider, ifxoledbc. 

For example: 

connStr="Provider=Ifxoledbc;Data Source=stores_demo@demo_on" 

Table 7-4 describes the specific connection string attributes for Informix OLE DB 

Provider. 

Table 7-4 Connection string attributes 


Data Source Database and Informix Server to which to connect. 

The syntax for the Data Source parameter is as 

follows: 

database@server 

If @server is not specified, the default database 

server is used (corresponding to the value specified 

by the client’s INFORMIXSERVER registry entry or 

environment variable). 

User ID The user ID used to connect to the Informix server 

Password The password for the user ID 

Persist Security Info Specifies whether the data source can keep 

authentication information such as the password 

Client_locale The client locale for the application which 

correspond to the locale used by the Windows OS 

Db_locale The database locale that was used when the 

database was created 

UNICODE Indicates whether to use IBM Informix GLS Unicode 

Controls and how the code set conversion to 

Unicode is done 

decasr8 If set, floating point numbers with a scale greater 

than 30 are returned as DBTYPE_R8 


7.3.3 Type mapping 


RSASWS or 

REPORTSTRINGASWSTRING 

A typical connection string for Informix OLE DB Provider looks similar to the 

following string: 

Data Source=stores_demo@demo_on; User ID=informix; Password=password; Persist 

Security Info=True; CLIENT_LOCALE=en_US.CP1252; DB_LOCALE=en_US.819 

The connection details about the Informix server must be stored in the registry 

using the setnet32.exe utility included in Client SDK. 

Informix OLE DB provider supports all the Informix data types, both built-in and 

extended. 

Table 7-5 lists the mappings between the standard OLE DB data types and 

specific Informix OLE DB types. 

Table 7-5 Informix specific type mapping table 


Enables you to control the data mapping for wide 

strings 

FBS or FETCHBUFFERSIZE The size in bytes of the buffer size used to send data 

to or from the database. Minimum value is 4096, 

Maximum 32767. Default is 4096. 

Informix SQL Informix OLE DB Provider 

BIGINT DBTYPE_I8 

BIGSERIAL DBTYPE_I8 

BLOB DBTYPE_BYTES 

BOOLEAN DBTYPE_BOOL 

BYTE DBTYPE_BYTES 

CLOB DBTYPE_STR 

DATETIME DBTYPE_DBDATE, DBTYPE_DBTIME, 

DBTYPE_DBTIMESTAMP 

DECIMAL DBTYPE_NUMERIC 

DISTINCT Same as underlying type 

FLOAT DBTYPE_R8

Informix SQL Informix OLE DB Provider 

INT8 DBTYPE_I8 

INTERVAL DBTYPE_STR if mapped as a string 

DBTYPE_Ix (8,4,2 or 1) if mapped as a numeric 

LIST DBTYPE_VARIANT 

LVARCHAR DBTYPE_STR 

MONEY (p

7.3.4 Cursors 

Informix OLE DB Provider Date and time precision 

DBTYPE_DBTIMESTAMP Day to fraction, day to hour, day to minute, and day to 

second 

Fraction to fraction, hour to fraction, and minute to 

fraction 

Month to fraction, month to hour, month to minute, and 

month to second 

Second to fraction 

Year to fraction, year to hour, year to minute, and year 

to second 

For a complete list of all the data type mapping, refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.oledb.doc/u 

sing990839.htm#using990839 

An ADO application uses cursors to move among the data that returned by a 

recordset. ADO defines the following types of cursors: 

► Forward-Only (adOpenForwardOnly): 

Provides a copy of the records at the time the Recordset was created. This is 

the default cursor type of ADO. 

► Static (adOpenStatic): 

Provides a static copy of the records. 

► Dynamic (adOpenDynamic): 

Provides a real-time copy of the records, new and altered records by other 

users are also included. 

► Keyset (adOpenKeyset): 

Provides a updateable copy of the records at the time the Recordset was 

created. Only existing records are included. 


Informix OLE DB Provider supports all these cursor types with some limitations 

regarding the use of extended data types and location of the cursor (client or 

server side). For example: 

► Updates of tables with extended data types are not allowed with client-side 

scrollable cursors. 

► Server-side scrollable cursors are not supported with simple large objects 

(BYTE and TEXT) or collections. 

► ROWIDs (internal columns added by the Informix server on non fragmented 

tables) are required on tables bookmarks and updates. 

Refer to the IBM Informix OLE DB Provider Programmer's Guide for a complete 

list of these caveats: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.oledb.doc/s 

ii-using-29878.htm#sii-using-29878 

7.3.5 Typical database operations 

In this section, we provide examples of how to use Informix OLE DB Provider to 

perform typical database operations against an Informix database. We cover 

operations such as executing SQL statements, selecting data, and handling 

errors from Informix OLE DB Provider. 

For general information about OLE DB architecture and programming, refer to: 

http://msdn.microsoft.com/en-us/library/ms713643%28v=VS.85%29.aspx 

Command 

You can execute SQL commands using an OLE DB provider through the 

ICommand interface. 

The application has to perform the following steps to execute an SQL statement: 

1. Call QueryInterface for IDBCreateCommand to check if commands are 

supported in the session. 

2. Call IDBCreateCommand::CreateCommand to create the command. 

3. Call ICommandText::SetCommandText to specify the SQL statement for the 

command. 

4. Call ICommand::Execute to execute the SQL statement. 


Example 7-3 demonstrates how to connect to the database and execute an 

UPDATE statement. In this example, we use the following operations and 

interfaces: 

1. Connect to the database 

a. Initialize common property options (prompt, DSN, user, and password). 

b. Get an Interface for properties: 

InterfacepIDBInitialize->QueryInterface(IID_IDBProperties) 

pIDBProperties->SetProperties() 

c. Get an Interface for creating session object: 

pIDBInitialize->QueryInterface(IID_IDBCreateSession) 

d. Create a session object: 

pCreateSession->CreateSession() 

2. Create a command object: 

a. Get an Interface for creating command object: 

pSession->QueryInterface(IID_IDBCreateCommand) 

b. Create the command object and get ICommandText: 


Interface:pCreateCommand->CreateCommand() 

3. Set the CommandText for the command object: 

pCommandText->SetCommandText() 

4. Execute the command: 

pCommandText->Execute() 

5. Clean up. 

Example 7-3 The command.cpp sample 

#define UNICODE 

#define _UNICODE 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

// CLSID For IBM-Informix Client Side OLE DB Provider 

const GUID CLSID_IFXOLEDBC= {0xa6d00422, 0xfd6c, 0x11d0, 

{0x80, 0x43, 0x0, 0xa0, 0xc9, 0xf, 0x1c, 0x59}}; 

#define CHECK(hr) if (((HRESULT)(hr)) < 0) {printf( "Error"); return(hr);}

int main() 

{ 

HRESULT hr = S_OK; 

IDBInitialize *pIDBInitialize; 

IDBCreateSession *pCreateSession; 

IDBCreateCommand *pCreateCommand; 

IUnknown *pSession; 

ICommandText *pCommandText; 

IDBProperties *pIDBProperties; 

DBPROP InitProperties[4]; 

DBPROPSET rgInitPropSet; 

_bstr_t bstrDsnName = "stores_demo@demo_on"; 

_bstr_t bstrUserName = "informix"; 

_bstr_t bstrPassWord = "password"; 

_bstr_t bstrCommand = (WCHAR *) L"UPDATE state SET sname = 'California' 

WHERE code = 'CA'"; 

CoInitialize( NULL ); 

// Instantiate a data source object 

CHECK( hr = CoCreateInstance((REFCLSID) CLSID_IFXOLEDBC, NULL, 

CLSCTX_INPROC_SERVER, IID_IDBInitialize, (void **) &pIDBInitialize)) 

// Set all Properties, Prompt, DSN, User and Password 

// Initialize common property options. 

for (ULONG i = 0; i < 4; i++ ) 

{ 

VariantInit(&InitProperties[i].vValue); 

InitProperties[i].dwOptions = DBPROPOPTIONS_REQUIRED; 

InitProperties[i].colid = DB_NULLID; 

InitProperties[1].vValue.vt = VT_BSTR; 

} 

InitProperties[0].dwPropertyID = DBPROP_INIT_PROMPT; 

InitProperties[0].vValue.vt = VT_I2; 

InitProperties[0].vValue.iVal = DBPROMPT_NOPROMPT; 

InitProperties[1].dwPropertyID = DBPROP_INIT_DATASOURCE; 

InitProperties[1].vValue.bstrVal = bstrDsnName; 

InitProperties[2].dwPropertyID = DBPROP_AUTH_USERID; 

InitProperties[2].vValue.bstrVal = bstrUserName; 

InitProperties[3].dwPropertyID = DBPROP_AUTH_PASSWORD; 

InitProperties[3].vValue.bstrVal = bstrPassWord; 

rgInitPropSet.guidPropertySet = DBPROPSET_DBINIT; 

rgInitPropSet.cProperties = 4; 

rgInitPropSet.rgProperties = InitProperties; 

// Get initialization properties.Interface 

CHECK (hr = pIDBInitialize->QueryInterface(IID_IDBProperties, 

(void**) &pIDBProperties)) 

CHECK(hr = pIDBProperties->SetProperties( 1, &rgInitPropSet)) 

CHECK( hr = pIDBProperties->Release()) 


Connect to the Database Server 

CHECK(hr = pIDBInitialize->Initialize()) 

// Get an Interface for creating Session Object 

CHECK( hr = pIDBInitialize->QueryInterface(IID_IDBCreateSession, 

(void **) &pCreateSession)) 

// Create a Session Object 

CHECK( hr = pCreateSession->CreateSession(NULL, IID_IUnknown, 

(IUnknown **) &pSession)) 

CHECK( hr = pCreateSession->Release()) 

// Create Command Object 

// Get an Interface for creating Command Object 

CHECK( hr = pSession->QueryInterface( IID_IDBCreateCommand, 

(void **) &pCreateCommand)) 

// Create Command Object and get ICommandText Interface 

CHECK( hr = pCreateCommand->CreateCommand(NULL, IID_ICommandText, 

(IUnknown **) &pCommandText )) 

CHECK( hr = pCreateCommand->Release()) 

// Set the CommandText 

CHECK( hr = pCommandText->SetCommandText(DBGUID_DBSQL, bstrCommand)) 

// Executing the Command 

CHECK( hr = pCommandText->Execute( NULL, IID_NULL, NULL, NULL, NULL)) 

printf( "Row Updated"); 

// Cleanup 

pCommandText->Release(); 

pCommandText = NULL; 

pSession->Release(); 

pSession = NULL; 

pIDBInitialize -> Uninitialize(); 

pIDBInitialize -> Release(); 

pIDBInitialize = NULL; 

} 

CoUninitialize(); 

return(0); 

Example 7-4 describes how to compile and run Example 7-3 on page 226. The 

connection string is constructed inside the program. No command line 

parameters are passed. 

Example 7-4 Output of the command.cpp sample 

C:\work>cl /EHsc /nologo command.cpp 

command.cpp 

C:\work>command 

Row Updated 

C:\work> 


Rowset 

A rowset is a set of rows, and each row has a number of columns of data. 

Rowsets are the main OLE DB objects that are used to expose data from a data 

source. 

You can create a rowset object with the following methods: 

► Explicitly create a rowset by calling IOpenRowset::OpenRowset(). 

► Execute an SQL statement such as SELECT that returns rows with a 

ICommand:Execute method. 

► Execute any method that returns a rowset or a schema rowset, for example, 

ColumnsRowset::GetColumnsRowset or IDBSchemaRowset::GetRowset. 

Example 7-5 demonstrates how to create a rowset object and retrieve metadata 

information. The operations and interfaces to initialize the session and connect to 

the database are always the same in a OLE DB application. This example also 

does the following operations: 

1. Connect to the database. 

2. Create a Command Object. 

3. Create a OpenRowSet Object: 

pCreateCommand->QueryInterface(IID_IOpenRowset) 

pIOpenRowset->OpenRowset() 

4. Obtain access to the IColumnsInfo interface from the rowset object: 

pRowset->QueryInterface(IID_IColumnsInfo) 

5. Retrieve the Column Information: 

pColumnsInfo->GetColumnInfo() 

6. Clean up. 

Example 7-5 The rowset.cpp sample 



#include 

#include 

#include 

#include 

#include 

#include 

#include 



{0x80, 0x43, 0x0, 0xa0, 0xc9, 0xf, 0x1c, 0x59}}; 


#define CHECK(hr) if (((HRESULT)(hr)) < 0) {printf( "Error"); return(hr);} 

int main() 

{ 




ITransactionJoin *pITransactionJoin; 

ICommandText *pCommandText; 

IOpenRowset *pIOpenRowset; 

IColumnsInfo *pColumnsInfo; 

IDBProperties* pIDBProperties; 



IDBCreateSession *pCreateSession = NULL; 

IDBCreateCommand *pCreateCommand = NULL; 

IRowset *pRowset = NULL; 

DBID TableID; 

DBPROPSET rgPropSets[1]; 

DBCOLUMNINFO *pDBColumnInfo; 

WCHAR *pStringsBuffer; 

ULONG lNumCols; 

int i=0; 

_bstr_t bstrDsnName = "stores_demo@demo_on"; 



_bstr_t TableName = L"customer"; 







for (ULONG i = 0; i < 4; i++ ) 

{ 





} 



















// Connect to the Database Server 

CHECK(hr = pIDBInitialize->Initialize()) 

// Get an Interface for creating Session Object 

CHECK( hr = pIDBInitialize->QueryInterface(IID_IDBCreateSession, 

(void **) &pCreateSession)) 

// Create a Session Object 

CHECK( hr = pCreateSession->CreateSession(NULL, IID_IUnknown, 

(IUnknown **) &pSession)) 

CHECK( hr = pCreateSession->Release()) 

// Create Command Object 

// Get an Interface for creating Command Object 

CHECK( hr = pSession->QueryInterface( IID_IDBCreateCommand, 

(void **) &pCreateCommand)) 

// Create Command Object and get ICommandText Interface 

CHECK( hr = pCreateCommand->CreateCommand(NULL, IID_ICommandText, 

(IUnknown **) &pCommandText )) 

CHECK( hr = pCreateCommand->Release()) 

// Create a OpenRowSet 

CHECK( hr = pCreateCommand->QueryInterface( IID_IOpenRowset, 

(void **)&pIOpenRowset )) 

TableID.eKind = DBKIND_NAME; 

TableID.uName.pwszName = TableName; 

)) 

CHECK( hr = pIOpenRowset->OpenRowset( NULL, &TableID, NULL, IID_IRowset, 

0, rgPropSets, (IUnknown **)&pRowset 

// Obtain access to the IColumnsInfo inteface, from the Rowset object 

CHECK( hr = pRowset->QueryInterface(IID_IColumnsInfo, (void ** ) 

&pColumnsInfo)) 

// Retrieve the Column Information 

CHECK( hr = pColumnsInfo->GetColumnInfo( &lNumCols, &pDBColumnInfo, 

&pStringsBuffer)) 

wprintf( L"\nTable : %s\nColumns :%d\nName\t\tType\tLength", 

TableID.uName.pwszName, lNumCols); 

for ( i=0; i

} 


wprintf( L"\n%s\t%d\t%ld", (pDBColumnInfo+i)->pwszName, 

(pDBColumnInfo+i)->wType, (pDBColumnInfo+i)->ulColumnSize); 

// Free the Column Information Interface 

CHECK( (hr = pColumnsInfo->Release())) 

// Cleanup 

pCommandText->Release(); 

pCommandText = NULL; 

pSession->Release(); 

pSession = NULL; 




} 


return(0); 

Example 7-6 shows the name, type, and length columns of the customer table. 

Example 7-6 Output of the rowset.cpp sample 

C:\work>cl /EHsc /nologo rowset.cpp 

rowset.cpp 

C:\work>rowset 

Table : customer 

Columns :7 

Name Type Length 

customer_num 3 4 

customer_type 129 1 

customer_name 129 32767 

customer_loc 3 4 

contact_dates 129 32767 

cust_discount 131 19 

credit_status 129 1 

C:\work> 

Large objects 

Large objects (simple and smart) do not require any special handling when using 

Informix OLE DB Provider. 

Smart large objects (BLOB and TEXT) support the ADO GetChunk() and 

AppendChunk() methods.

Example 7-7 demonstrates how to retrieve a CLOB column using the GetChunk() 

method from the ADO library in C++. This example fetches the first three rows of 

the catalog table from the sample stores_demo database and displays the data 

for the catalog_number and advert_descr columns. 

Example 7-7 The select.cpp sample 

#include 

#include 

#import "c:\program files\common files\system\ado\msado15.dll" rename 

("EOF","adoEOF") no_namespace 

#define CREATEiNSTANCE(sp,riid) { HRESULT _hr =sp .CreateInstance( __uuidof( riid 

) ); \ 

if (FAILED(_hr)) _com_issue_error(_hr); } 

#define RsITEM(rs,x) rs->Fields->Item[_variant_t(x)]->Value 

#define UC (char *) 

struct InitOle { 

InitOle() { ::CoInitialize(NULL); } 

~InitOle() { ::CoUninitialize(); } 

} _init_InitOle_; 

void main(){ 

_RecordsetPtr spRS; 

_ConnectionPtr spCON; 

_variant_t varBLOB; 

long lDataLength = 0; 

int nrows=3; 

try{ 

CREATEiNSTANCE(spCON,Connection); 

spCON->Provider="ifxoledbc"; 

spCON->ConnectionString = L"Data Source=stores_demo@demo_on;" 

L"User ID=informix; Password=password;"; 

// Connect to the database 

spCON->Open( "", "", "", -1 ); 

CREATEiNSTANCE(spRS,Recordset) 

spRS->PutRefActiveConnection( spCON ); 

spRS->Open(_bstr_t("catalog"),vtMissing, adOpenForwardOnly, 

adLockOptimistic,adCmdTable); 

while( (spRS->adoEOF == false) && nrows>0 ){ 

nrows--; 

printf("catalog_num = %s\n", UC _bstr_t(RsITEM(spRS,"catalog_num"))); 

// Get the size of the large object 

lDataLength = spRS->Fields->Item["advert_descr"]->ActualSize; 


if(lDataLength > 0) { 

// Call GetChunk to retrieve the Blob data 

VariantInit(&varBLOB); 

varBLOB = spRS->Fields->Item["advert_descr"]->GetChunk(lDataLength); 

printf("advert_descr = %s\n", UC _bstr_t(varBLOB)); 

} 

// Move the cursor to the next row 

spRS->MoveNext(); 

} 

spRS->Close(); 

spCON->Close(); 

} 

catch( _com_error &e){ 

_bstr_t bstrSource(e.Source()); 

_bstr_t bs = _bstr_t(" Error: ") + _bstr_t(e.Error()) + 

_bstr_t(" Msg: ") + _bstr_t(e.ErrorMessage()) + 

_bstr_t(" Description: ") + _bstr_t(e.Description()); 

printf("Error %s\n", bs); 

} 

} 

#undef UC 

Example 7-8 shows the content of the output. 

Example 7-8 Output of the select.cpp sample 

C:\work>cl /EHsc /nologo select.cpp /DWINVER=0x0600 

select.cpp 

C:\work>select 

catalog_num = 10001 

advert_descr = Brown leather. Specify first baseman's or infield/outfield 




C:\work> 

Errors 

Informix OLE DB Provider supports the ISupportErrorInfo interface. 

Applications can retrieve information about an OLE DB error using this interface. 

Methods such as IErrorRecords->GetErrorInfo(), 

IErrorInfo->GetDescription() and IErrorInfo->GetSource() are fully 

supported by Informix OLE DB Provider. 


Example 7-9 illustrates how to use these methods. This example retrieves the 

error information directly after the IDBInitialize->Initialize() function call. 

Because error handling should be done after every use of an interface function, it 

is a good practice to create an error handle routine to avoid code redundancy. 

Example 7-9 The errorinfo.cpp sample 



#include 

#include 

#include 

#include 

#include 

#include 

#include 



{0x80, 0x43, 0x0, 0xa0, 0xc9, 0xf, 0x1c, 0x59}}; 

#define CHECK(hr) if (((HRESULT)(hr)) < 0) {printf( "Error"); return(hr);} 

HRESULT GetDetailedErrorInfo( 

HRESULThresult, 

IUnknown *pBadObject, 

GUID IID_BadIntereface); 

int main() 

{ 




IDBProperties* pIDBProperties; 



IDBCreateSession *pCreateSession = NULL; 

IErrorInfo *pErrorInfo = NULL; 

IErrorInfo *pErrorInfoRec = NULL; 

IErrorRecords *pErrorRecords = NULL; 

ISupportErrorInfo *pSupportErrorInfo = NULL; 

ULONG i,ulNumErrorRecs; 

BSTR bstrDescriptionOfError = NULL; 

BSTR bstrSourceOfError = NULL; 

_bstr_t bstrDsnName = "wrong_db@demo_on"; // WRONG DATABASE 










for (ULONG i = 0; i < 4; i++ ) 

{ 





} 


















// Connect to the Database Server 

hr = pIDBInitialize->Initialize(); 

if (hr < 0) { 

pIDBInitialize->QueryInterface(IID_ISupportErrorInfo, 

(LPVOID FAR*)&pSupportErrorInfo); 

pSupportErrorInfo->InterfaceSupportsErrorInfo(__uuidof(pIDBInitialize)); 

GetErrorInfo(0,&pErrorInfo); 

//Get the IErrorRecord interface and get the count of error recs. 

pErrorInfo->QueryInterface(IID_IErrorRecords,(LPVOID FAR*)&pErrorRecords); 

pErrorRecords->GetRecordCount(&ulNumErrorRecs); 

//Get the error record, (we only get the first one) 

pErrorRecords->GetErrorInfo(0, GetUserDefaultLCID(), &pErrorInfoRec); 

pErrorInfoRec->GetDescription(&bstrDescriptionOfError); 


pErrorInfoRec->GetSource(&bstrSourceOfError); 

printf("ERROR!\nResult of 0x%0x (%ld) returned\n",(long)hr,(long)hr); 

printf("Error Source: %S\n",bstrSourceOfError); 

printf("Error Description: %S\n", bstrDescriptionOfError); 

pErrorInfo->Release(); 

pErrorRecords->Release(); 

pSupportErrorInfo->Release(); 

pErrorInfoRec->Release(); 

SysFreeString(bstrSourceOfError); 

SysFreeString(bstrDescriptionOfError); 

} // if 

/* ... some useful code here .... */ 

} 





return(0); 

Example 7-10 shows the output of Example 7-9 on page 235. We use a 

non-existent database for the connection. An error is expected during 

initialization. 

Example 7-10 Output of the errorinfo.cpp sample 

C:\work>cl /EHsc /nologo errorinfo.cpp 

errorinfo.cpp 

C:\work>errorinfo 

ERROR! 

Result of 0x80004005 (-2147467259) returned 

Error Source: Ifxoledbc 

Error Description: EIX000: (-329) Database not found or no system permission. 

C:\work> 

7.4 Visual Basic, ADO.NET, and SQL Server 

ActiveX and COM objects are a core component of any Windows operating 

system. For this reason, OLE DB providers are used extensively by many 

Windows applications. In this section, we describe how to use Informix OLE DB 


Provider with some of the available Microsoft technologies and applications, such 

as ADO.NET or Microsoft SQL Server. 

7.4.1 OLE DB with Visual Basic 

Visual Basic (VB) is a programming language developed by Microsoft that 

focuses on the use of COM objects. Visual Basic is design to be easy to learn 

and to allow the development of database applications with far less effort than C 

or C++ languages. ADO and Informix OLE DB Provider are widely used with 

Visual Basic. 

In this section, we demonstrate how to use Informix OLE DB Provider to access 

an Informix database using a VBScript that is based on Visual Basic. 

Select data 

Example 7-11 shows how to query the state table using a recordset with a 

VBScript file. We open the recordset using a static server cursor (adUseServer=2 

and adOpenStatic=3). 

Example 7-11 The select.vbs script 

' Create the ADO objects 

set cx=createobject("ADODB.Connection") 

set cr=createobject("ADODB.Recordset") 

' Set the connection string 

cx.provider="Ifxoledbc" 

cx.connectionstring="Data Source=stores_demo@demo_on;" 

' Open the Connection 

cx.open 

set cr.activeconnection=cx 

cr.cursorlocation=2 

' Open the Recordset 

cr.open "SELECT * FROM state WHERE code='CA'", cx, 2, 3 

WScript.Echo cr.fields("sname") 

Example 7-12 shows the output of the this script. 

Example 7-12 Output of the select.vbs script 

c:\work>select.vbs 

California 

c:\work> 


Comparing this example with Example 7-5 on page 229, which is written on C++, 

shows how easy it is to use OLE DB with Visual Basic. 

Example 7-13 demonstrates how to scroll through a recordset. 

Example 7-13 The scroll.vbs script 


set cx=createobject("ADODB.Connection") 

set cr=createobject("ADODB.Recordset") 

set cm=createobject("ADODB.Command") 


cx.provider = "Ifxoledbc.2" 

cx.Open "Data Source=stores_demo@demo_on" 

' Set the Command SQL text 

cm.ActiveConnection = cx 

cm.CommandText = "SELECT * FROM state" 

' Open the cursor 

cr.CursorLocation = 3 ‘ adUseClient 

cr.Open cm 

WScript.Echo "First row: " & cr.fields("sname") 

' Scroll to the last element in the recordset 

cr.MoveLast 

WScript.Echo "Last row : " & cr.fields("sname") 

We use the MoveLast() method to position the cursor in the last record, as shown 

in the output in Example 7-14. 

Example 7-14 Output of the scroll.vbs script 

c:\work>scroll.vbs 

First row: Alaska 

Last row : Puerto Rico 

c:\work> 

Add new data 

Example 7-15 demonstrate how to add a new record to a table using the 

AddNew() method. After adding a new record to the table, the code opens a 

cursor and positions it at the end of the recordset to retrieve the last inserted row. 

Example 7-15 The addnew.vbs script 


set cx = CreateObject("ADODB.Connection") 

set cr = CreateObject("ADODB.Recordset") 


cx.provider = "Ifxoledbc" 


cx.connectionstring = "Data Source=stores_demo@demo_on;" 

cx.Open 

Set cr.activeconnection = cx 

' Open the recordset 

cr.Open "SELECT * FROM state", cx, 3, 2 

' Add a new record to the recordset 

cr.AddNew 

cr.fields("code") = "UN" 

cr.fields("sname") = "Unkown" 

cr.fields("sales_tax") = "0.0" 

' Update the database table 

cr.Update 

cr.Close 

' Retrieve the new inserterd row 

cr.open "SELECT * FROM state", cx, 3, 3 

cr.MoveLast 

WScript.Echo cr.fields("sname") 

Example 7-16 shows the value of the sname column after the update operation. 

Example 7-16 Output of the addnew.vbs script 

c:\work>addnew.vbs 

Unkown 

c:\work> 

7.4.2 ADO.NET and the OLEDB bridge 

In addition to ADO, developers can also use Informix OLE DB Provider with 

ADO.NET. Similar to ADO but within the .NET Framework, ADO.NET is a set of 

.NET components that are used to retrieve, manipulate, and update data from a 

data source. 

One of the .NET data providers that is included with ADO.NET is the Microsoft 

OLE DB Provider for .NET. This .NET provider acts as bridge between the .NET 

framework and standard OLE DB providers so that developers can use .NET 

technology with a database server, even if there is no specific .NET data provider 

for that particular database. 

IBM has specific .NET providers to access an Informix database: 

► IBM Informix .NET Provider 

► IBM Data Server Provider for .NET 

However, developers can use Informix OLE DB Provider through the Microsoft 

OLE DB .NET Provider. 


Example 7-17 demonstrates how to use Informix OLE DB Provider with a .NET 

application. The connection string for Informix OLE DB Provider is the same. 

Refer 7.3.2, “Connecting to database” on page 221 for the complete syntax. 

Example 7-17 The getoledb.cs sample 

using System; 

using System.Data; 

using System.Data.OleDb; 

class sample { 

static void Main(string[] args) { 

OleDbConnection con = new OleDbConnection(); 

con.ConnectionString = "Provider=Ifxoledbc;" 

+" Data Source=stores_demo@demo_on; User ID=informix;" 

+" Password=password"; 

DataSet ds = new DataSet(); 

string sql = "SELECT first 3 * FROM STATE"; 

OleDbDataAdapter da = new OleDbDataAdapter(sql,con); 

da.Fill(ds,"state"); 

foreach(DataRow dr in ds.Tables[0].Rows) { 

Console.WriteLine(dr["code"]); 

Console.WriteLine(dr["sname"]); 

Console.WriteLine(dr["sales_tax"]); 

} 

con.Close(); 

con.Dispose(); 

} 

} 

Example 7-18 demonstrates how to compile and run this .NET example. 

Example 7-18 Output of the getoledb.cs sample 

c:\work>csc.exe /nologo getoledb.cs 

c:\work>getoledb 

AK 

Alaska 

0.00000 

HI 

Hawaii 

0.04000 

CA 


California 

0.08250 

c:\work> 

7.4.3 SQL Server 

Using Informix OLE DB Provider, you can select data from an Informix database 

directly from Microsoft SQL Server. 

SQL Server uses OLE DB to create linked servers and to retrieve data from any 

OLE DB data source. 

There are no specific steps to configure or to use Informix OLE DB Provider with 

SQL Server as a linked server. If Informix OLE DB Provider is installed and 

configured correctly, SQL Server can use it to connect to an IBM Informix 


We describe how to set up a linked server using the Informix provider in this 

section. 


Figure 7-1 shows the New Linked Server dialog box where you set the 

connection details for Informix OLE DB Provider. 

Figure 7-1 New Linked Server dialog box 

In this dialog box, set the following fields: 

► Linked server: Specify the name for the SQL Server to link. 

► Provider: Choose IBM Informix OLE DB Provider from the drop-down list. 

► Product name: Specify the name of the Informix provider, which in this 

example is ifxoledbc. 

► Data source: Specify the name of the data source as database@server. 

► Provider string: Specify any additional connection string parameters that the 

provider uses. 


The user ID for the Informix database server might differ from the one that is 

used with SQL Server. If so, you need to set a remote user mapping. Figure 7-2 

shows a user mapping between the sa and informix users. 

Figure 7-2 Linked Server Properties: Security options 

You can also create linked servers using only SQL statements. Example 7-19 

illustrates how to create a linked server to connect to the demo_on Informix 

instance. We use the same connection details shown in Figure 7-1 on page 243. 

Example 7-19 Linked Server SQL script 

EXEC master.dbo.sp_addlinkedserver 

@server = N'demo_on', 

@srvproduct=N'ifxoledbc', 

@provider=N'ifxoledbc', 

@datasrc=N'stores7@demo_on', 

@provstr=N'' 

EXEC sp_addlinkedsrvlogin 'demo_on',false,'sa','informix','password' 

SELECT * FROM demo_on.stores7.informix.customer 


The last SQL statement in the script uses the linked server to retrieve the data 

from the customer table: 

SELECT * FROM demo_on.stores7.informix.customer 

For more information about linked servers, refer to: 

http://msdn.microsoft.com/en-us/library/ms188279.aspx 

7.5 Troubleshooting and tracing 

7.5.1 Typical errors 

In this section, we discuss typical errors that can occur when using Informix OLE 

DB Provider and how to enable the tracing facility to collect diagnostic 

information. 

Most errors encountered when using Informix OLE DB Provider are due to an 

incorrect setup or an invalid connection string passed to the provider. 

Informix OLE DB Provider uses the same connectivity libraries as other 

components of Client SDK. It also uses the information that is stored in the 

registry through the setnet32.exe utility for the database server connection. 

It is always a good practice to test this basic connectivity using the iLogin utility 

that is included in the Client SDK directory. 

Provider not found 

Here, we explain the reason and the solution for a “Provider not found” error. 

Reason 

This error appears if the Windows operating system fails to locate the OLE DB 

provider class that is specified by the application. 

Solution 

During the installation of Client SDK, the OLE DB provider is registered 

automatically within the Windows registry. You can register Informix OLE DB 

Provider manually using the regsvr32 utility as follows: 

regsvr32.exe %INFORMIXDIR%\bin\ifxoledbc.dll 

If you are running a 64-bit version of Windows, make sure that you register the 

provider using the correct version of the regsvr32 binary. Otherwise, it can 


happen that the 32-bit provider is registered as a 64-bit provider (or vice versa) 

and the Windows operating system will fail to find and load the provider. 

You can verify that the provider library is registered correctly by examining the 

Windows registry. Example 7-20 shows the registry entry for 32-bit and 64-bit 

Informix OLE DB Provider. Remember that the name of the Informix provider is 

ifxoledbc. 

Example 7-20 Informix OLE DB registry keys 

C:\work>c:\windows\syswow64\reg query 

"HKEY_CLASSES_ROOT\CLSID\{A6D00422-FD6C-11D0-8043-00A0C90F1C59}\InprocServer32" 

HKEY_CLASSES_ROOT\CLSID\{A6D00422-FD6C-11D0-8043-00A0C90F1C59}\InprocServer32 

(Default) REG_SZ C:\Program Files 

(x86)\IBM\Informix\Client-SDK\bin\ifxoledbc.dll 

ThreadingModel REG_SZ Both 

C:\work>c:\windows\system32\reg query 

"HKEY_CLASSES_ROOT\CLSID\{A6D00422-FD6C-11D0-8043-00A0C90F1C59}\InprocServer32" 

HKEY_CLASSES_ROOT\CLSID\{A6D00422-FD6C-11D0-8043-00A0C90F1C59}\InprocServer32 

(Default) REG_SZ C:\Program 

Files\IBM\Informix\Client-SDK\bin\ifxoledbc.dll 

ThreadingModel REG_SZ Both 

C:\work> 

Failed to load the Ifxoledbc.dll 

Here, we explain the reason and the solution for a “Failed to load the 

Ifxoledbc.dll” error. 

Reason 

The application fails to load Informix OLE DB Provider or one of its libraries. 

Solution 

The value of INFORMIXDIR (as a environment variable or in the registry) should 

be the directory where Client SDK is installed. Ensure that the environment 

variable PATH contains the %INFORMIXDIR%\bin directory. For example: 

PATH=C:\Program Files\IBM\Informix\Client-SDK\bin;%PATH% 

When an application loads Informix OLE DB Provider, Client SDK libraries that 

the provider needs for communication and registry access are loaded from the 

directory that is used in the registration process. 


On 64-bit version of Windows operating system, ensure that the PATH and 

INFORMIXDIR variables are set correctly for all users. Some applications, such 

as SQL Server, are executed under credentials that are different than the logged 

user and that can have different settings for this variables. 

Failed to connect to the database 

Here, we explain the reason and the solution for a “Failed to connect to the 

database” error. 

Reason 

The most common reason for this type of error is due to invalid parameters in the 

connection string or invalid connectivity information. 

Solution 

If the application is getting an Informix OLE DB error, it has managed to load 

Informix OLE DB Provider, but it is failing during connection. 

For any connection error, always ensure that the basic connectivity works. 

Testing whether the client system has access to the database using the iLogin 

utility can help to narrow the problem. 

If iLogin fails, verify that the connection parameters for the database (server 

name, port number, host name, and so on) are correct. Use the setnet32.exe 

utility to verify that the information stored in the registry is valid. 

The user credentials (user ID and password) can also be set in the registry using 

the setnet32.exe utility. Verify that both the user ID and password are valid. 

The majority of the connection string parameters must be included exactly as 

they appear in Table 7-4 on page 221. Invalid parameters are ignored and can 

cause an error connection. See Table 7-7 for examples of valid parameters. 

Table 7-7 Valid parameters 

Valid Invalid 

Data Source DataSource, DSN 

User ID UserID, UID 

Password PWD 

If you are using GLS variables (Client_Locale or Db_locale), make sure that 

they are set correctly. If you do not use UNICODE, the code set part of 

Client_Locale should be the same as your operating system. Db_Locale should 

be your database locale. 


7.5.2 Tracing 

Failure when handling database data 

Here, we explain the reason and the solution for a “Failed when handling 

database data” error. 

Reason 

These types of errors are caused by using the wrong data type when accessing 

Informix tables. 

Solution 

Informix OLE DB Provider requires additional functions and tables in the 

sysmaster database to handle Informix data types correctly. These objects are 

created when running the coledbp.sql SQL script. 

This script is located in the %INFORMIXDIR%\etc directory, and must be executed 

against the sysmaster database as the informix user. 

If you are upgrading from an older version of Client SDK, remove these objects 

by running the doledbp.sql script from the old client before using the new 

coledbp.sql script. 

Tracing is useful when diagnosing application problems such as SQL errors or 

unexpected behaviors and can even be used for performance analysis. 

A developer can set the following types of tracing when using Informix OLE DB 

Provider: 

► Informix OLE DB Trace 

► SQLIDEBUG 

Informix OLE DB Trace 

Informix OLE DB Trace is specific to Informix OLE DB Provider. You can set the 

IFXOLEDBCTRACE environment variable to point to the location of the trace file, 

for example: 

IFXOLEDBCTRACE=oledbtrace.txt 

The trace file that is generated contains the calls to all the OLE DB interfaces that 

the provider uses. 

Example 7-21 shows a typical Informix OLE DB trace file. 

Example 7-21 OLE DB trace 

Wed Jun 30 13:59:01 2010 


A44: 53C Enter Clsfact::QueryInterface 

Object Address: 0x032C2CB8 

A44: 53C Enter Clsfact::AddRef 


A44: 53C Exit Object Address: 0x032C2CB8 hr=2 

qi: 032C2CB8 (pif 032C2CB8) 

A44: 53C Enter Clsfact::Release 






A44: 53C Enter Clsfact::Release 



A44: 53C Enter Clsfact::QueryInterface 





... 

In addition to the OLE DB interfaces, the trace facility collects the return value for 

any method that is used during the OLE DB session, as shown in Example 7-22. 

Example 7-22 Entry and exit points OLE DB trace 

A44: 53C Enter Datasrc::QueryInterface 


A44: 53C Enter Datasrc::AddRef 

A44: 53C Exit Object Address: 0x032CC370 hr=2 

A44: 53C Enter Datasrc::Release 



A44: 53C Enter Datasrc::XIDBProperties::SetProperties 

A44: 53C Exit Object Address: 0x032CC38C hr=0 


A44: 53C Enter Datasrc::XIDBProperties::SetProperties 



A44: 53C Enter Datasrc::XIDBInitialize::Initialize 



A44: 53C Enter Datasrc::XIDBProperties::GetProperties 




A44: 53C Enter Datasrc::XIDBCreateSession::CreateSession 

SQLIDEBUG 

SQLI is the communication protocol used by Client SDK. SQLIDEBUG is a trace 

facility of all the messages between an Informix client and an Informix database 

server. This trace is common to all the Client SDK components (ESQL/C, ODBC, 

OLE DB, and so on). 

You can find a description and how to enable SQLIDEBUG in 3.3.6, 

“Troubleshooting” on page 117. 

When diagnosing a performance problem, sometimes it is useful to collect an 

SQLIDEBUG trace to have an idea of where the delay occurs. Using the summary 

option when processing the SQLIDEBUG file with sqliprint produces a detailed 

description of all the messages between the client and server, as shown in 

Example 7-23. 

Example 7-23 Sqliprint summary output 

>>>>>>>>>>>>>>>>>> SUMMARY INFORMATION >>>>CLIENT ELAPSED CLOCK TIME (sec): 0.047000 

>>>>>>>>>>SERVER+NETWORK CLOCK TIME (sec): 0.000000 

FROM C->S 

Msg occured Total Avg Min Max 

------------------------------------------------------------------ 

SQ_PREPARE 1 0.000000 0.000000 0.000000 0.000000 

SQ_ID 4 

SQ_CLOSE 1 

SQ_RELEASE 2 

SQ_EOT 7 

SQ_NDESCRIBE 1 

SQ_SFETCH 1 0.000000 0.000000 0.000000 0.000000 

SQ_WANTDONE 1 

SQ_EXIT 1 

SQ_INFO 1 

SQ_RET_TYPE 1 

SQ_INTERNALVER 1 

SQ_PROTOCOLS 1 

------------------------------------------------------------------ 

FROM S->C 

Msg occured Total Avg Min Max 

------------------------------------------------------------------ 


UNKNOWN 1 

SQ_DESCRIBE 1 0.000000 0.000000 0.000000 0.000000 

SQ_EOT 6 

SQ_TUPLE 1 

SQ_TUPID 1 

SQ_PROTOCOLS 1 

------------------------------------------------------------------ 

======================================================================= 

COMMAND TEXT INFORMATION (first 99 are listed) 

a( b) CMD[##]= ' first 60 bytes of cmd text ' 

where a = 'P'repare, or 'N'ot prepared, and b = length of command string 

----------------------------------------------------------------------- 

P( 28) CMD[ 0]='SELECT rowid, * FROM state;' 

----------------------------------------------------------------------- 

======================================================================= 

Fetch Array feature not used 

OPTOFC feture not used 

Number of open/reoptimzation encountered = 0 

Number of C->S message send = 22 

Number of S->C message send = 21 

Number of prepare statements encountered = 1 

Number of execute statements encountered = 0 

Number of singleton select encountered = 0 

Number of open cursor encountered = 0 

Number of close cursor encountered = 1 

Number of non-blob put = 0, averge size of each put is 0.000000 

Number of non-blob fetch = 1, averge size of each fetch is 25.000000 

Number of blob put = 0, averge size of each put is 0.000000 

Number of blob fetch = 0, averge size of each fetch is 0.000000 

>>>>>>>>>>>>>>> END SUMMARY INFORMATION


Chapter 8. Working with .NET data 

providers 

8 

This chapter describes the .NET providers that are available for working with an 

Informix database server. It includes the following topics: 

► Informix and .NET data providers 


► Developing a .NET application 

► Visual Studio Add-In for Visual Studio 


8.1 Informix and .NET data providers 

A .NET data provider is a .NET assembly that lets .NET applications access and 

manipulate data in a database by implementing several interfaces that follow the 

Microsoft ADO.NET architecture. Any application that can be executed by the 

Microsoft .NET Framework can use a .NET data provider. 

IBM provides the following .NET data providers to work with an IBM Informix 

database: 

► IBM Infomix .NET Provider 

► IBM Data Server Provider for .NET 

Both providers rely on internal calls to the ODBC and CLI drivers. They are not 

100% managed-code providers. 


This chapter describes the .NET providers that are available to connect to an 

IBM Informix database. We explain how to configure and test the connectivity 

with both Infomix .NET Provider and Data Server Provider for .NET. 

8.2.1 IBM Informix .Net Provider 

Informix .NET Provider is part of the Informix Client Software Development Kit 

(Client SDK). Informix .NET Provider is certified to work on both 32-bit and 64-bit 

editions of Windows XP, Windows Vista, Windows Server 2003, Windows Server 

2008, and Windows 7. 

The provider requires that Microsoft .NET Framework SDK 1.1 or higher is 

already installed on the computer. The provider is installed by default when 

performing a complete installation of Client SDK. 

Informix .NET Provider supports the following Informix database servers: 

► IBM Informix 10.00, 11.10, and 11.50 

► IBM Informix Extended Parallel Server 8.50 and later 

The assembly name of the Informix .NET Provider is IBM.Data.Informix. 

The assembly files are located in the Client SDK directory. The provider for a 

.NET 1.1 application is in the %INFORMIXDIR%\netf11 directory. For a .NET 2.0 

and above, use the provider located in the %INFORMIXDIR\netf20 directory. 


The installation process registers two strong-named assemblies in the global 

assembly cache (GAC). 

Table 8-1 shows Informix .NET Provider assembly versions. 

Table 8-1 Informix .NET Provider assembly versions 

.NET framework Assembly version 

1.1 2.81.0.0 

2.0 and above 3.0.0.2 

The assemblies are registered in the common section of the GAC (GAC_MSIL). 

Thus, only one version of the provider (32-bit or 64-bit) can be stored in the GAC 

at a time. 

Note: There is no 64-bit version of the .NET 1.1 Framework, so the .NET 1.1 

Provider is not installed on a Windows 64-bit platform. 

8.2.2 IBM Data Server Provider for .NET 

Data Server Provider for .NET is included in the IBM Data Server Package. The 

provider supports multiple IBM data servers, including IBM Informix (11.x) and 

DB2. 

As with Informix .NET Provider, the Data Server Provider for .NET is not 100% 

managed code. Thus, it requires the DB2 CLI component for communication with 

the database. 

The following Data Server providers for an Informix database are available: 

► IBM.Data.DB2 is the preferred .NET provider when developing new 

applications. 

► IBM.Data.Informix is the .NET provider assembly that is normally used to 

migrate an application that is developed using Informix .NET Provider. 

The assembly files are located in the netf20 subdirectory under the Data Server 

Client directory, which by default is C:\Program Files\IBM\IBM DATA SERVER 

DRIVER\netf20. 

Note: The 64-bit version of the Data Server Client Package also includes the 

32-bit drivers. 

Chapter 8. Working with .NET data providers 255

Both providers have the same assembly version, 9.0.0.2. Table 8-2 shows the 

Data Server Provider for .NET assembly version. 

Table 8-2 Data Server Provider for .NET assembly versions 

.NET Provider Assembly version 

IBM.Data.DB2 9.0.0.2 

IBM.Data.Informix 9.0.0.2 


Informix .NET Provider uses communication libraries internally as do the other 

drivers that are included in Client SDK. Thus, it uses the same connectivity 

information that is normally stored in the registry through the use of the 

setnet32.exe utility. 

When there is no specific tool to verify the connectivity with Informix .NET 

Provider, you can use a simple .NET application to test it. 

The Microsoft .NET Framework SDK is required to use a .NET provider that 

contains a .NET language compiler. 

Example 8-1 shows a simple C code sample that verifies the connection with the 

database server. This example takes the connection string as the first argument 

and uses it to connect to the database. 

Example 8-1 A connect.cs sample 

using System; 


using IBM.Data.Informix; 

class Connect 

{ 

static void Main(string[] args) 

{ 

IfxConnection conn; 

if (args.Length>0) { 

try { 

conn = new IfxConnection(args[0]); 

conn.Open(); 

Console.WriteLine("Connected"); 

Console.WriteLine(String.Format("Server Type: {0}, Server 

Version: {1}", conn.ServerType, conn.ServerVersion)); 


Console.WriteLine(String.Format("Database: {0}", 

conn.Database)); 

} 

catch (Exception e) { 

Console.WriteLine(e.Message); 

} 

} 

else 

Console.WriteLine("Need a connection string as argument\n e.g: 

\"Host=kodiak;Service=9088;Server=demo_on;Database=stores_demo;User 

ID=informix;password=;\"\n"); 

} 

} 

Example 8-2 shows how to compile and run Example 8-1 on page 256. 

Example 8-2 Output of the connect.cs sample 

C:\work>csc.exe /R:%INFORMIXDIR%\bin\netf20\IBM.Data.informix.dll /nologo 

connect.cs 

C:\work>connect "Server=demo_on;Database=stores_demo" 

Connected 

Server Type: Informix, Server Version: 11.50.0000 FC6 

Database: stores_demo 

C:\work> 

If the connection information for the Informix server is stored in the registry, the 

only parameter that is required in the connection string is the name of the 

database server. The remainder of the information, such as Host or Service, is 

taken from the registry. 

At compile time, you must pass the assembly as a reference to the csc.exe 

compiler using the /R parameter. For example: 

/R:%INFORMIXDIR%\bin\netf20\IBM.Data.Informix.dll 

If you want to use the Data Server provider, the reference path is as follows: 

/R:”C:\Program Files (x86)\IBM\IBM DATA SERVER DRIVER\bin\netf20\IBM.Data.Informix.dll” 


Example 8-3 shows how to compile and execute the sample with Data Server 

Provider for .NET. 

Example 8-3 Data Server connect.cs sample 

C:\work>csc.exe /R:"C:\Program Files (x86)\IBM\IBM DATA SERVER 

DRIVER\bin\netf20\IBM.Data.Informix.dll" /nologo connect.cs 

C:\work>connect "Server=kodiak:9089;Database=stores_demo;User 

ID=informix;password=password;" 

Connected 

Server Type: IDS/NT64, Server Version: 11.50.0000 

Database: STORES_DEMO 

C:\work> 

Data Server Provider for .NET includes a connection tool called testconn20.exe 

that you can use to test the connection with the database. Example 8-4 shows a 

typical output of the testconn20.exe utility. 

Example 8-4 Output of the testconn20.exe utility 

C:\work>testconn20.exe "server=kodiak:9089; database=stores_demo; uid=informix; 

pwd=password;" 

Step 1: Printing version info 

.NET Framework version: 2.0.50727.3603 

DB2 .NET provider version: 9.0.0.2 

DB2 .NET file version: 9.7.2.2 

Capability bits: ALLDEFINED 

Build: 20100514 

Factory for invariant name IBM.Data.DB2 verified 

VSAI assembly version: 9.1.0.0 

VSAI file version: 9.7.1.53 

Elapsed: 1.015625 

Step 2: Validating db2dsdriver.cfg against db2dsdriver.xsd schema file 

C:\PROGRA~1\IBM\IBMDAT~2\cfg\db2dsdriver.cfg against C:\Program 

Files\IBM\IBM DATA SERVER DRIVER\cfg\db2dsdriver.xsd 

Elapsed: 0.015625 

Step 3: Connecting using "server=kodiak:9089; database=stores_demo; 

uid=informix; pwd=password;" 

Server type and version: IDS 11.50.0000 

Elapsed: 0.46875 

Step 4: Selecting rows from informix.systables to validate existance of 

packages 

SELECT * FROM informix.systables 


Elapsed: 0.171875 

Step 5: Calling GetSchema for tables to validate existance of schema functions 

Elapsed: 0.21875 

Test passed. 

C:\work> 

8.3 Developing a .NET application 

This section describes the connection string attributes for two Informix .NET 

providers and provides samples of basic database operations. 

8.3.1 Connecting to the database 

In this section, we describe the connection string attributes for Informix .NET 

Provider and Data Server Provider for .NET 

Informix .NET Provider connection attributes 

Table 8-3 lists the connection attributes that Informix .NET Provider supports. 

Table 8-3 Informix .NET Provider connection string attributes 

Attribute Description Default 

Client Locale, 

Client_Locale 

Locale used on the application en_us.1252 

Connection Lifetime Time in seconds that a connection is 

allowed in the pool 

Database, DB Database to connect to 

Database Locale, 

DB_LOCALE 

Locale of the database en_US.819 

DELIMIDENT If set, any string within double quotes (") 

is treated as an identifier, and any string 

within single quotes (’) is treated as a 

string literal 

Enlist Enables or disables automatic enlistment 

in a distributed transaction 

Chapter 8. Working with .NET data providers 259 

0 

y 

true

Attribute Description Default 

Exclusive, XCL if set the database is open in exclusive 

mode 

Host Name or IP address of the system on 

which the Informix server is running 

Max Pool Size Maximum number of connections 

allowed in the pool 

Min Pool Size Minimum number of connections allowed 

in the pool 

Optimize OpenFetchClose, 

OPTOFC 

Packet Size, Fetch Buffer 

Size, FBS 


Reduces the number of client-server 

messages when using cursors 

Size in bytes of the buffers used to send 

data to or from the server 

Password, PWD Password associated with the User ID 

Persist Security Info If set the security-sensitive information, 

such as the password, is returned as part 

of the connection string 

No 

localhost 

100 

0 

0 

32767 

false 

Pooling Enable Connection Pooling true 

Protocol, PRO Communication protocol 

Server Name or alias of the Informix server 

Service Service name or port number used by the 

server for incoming connection 

Skip Parsing If set, there is no internal SQL parsing it 

increases performance but the SQL must 

be valid 

UserDefinedTypeFormat Changes the mapping of UDTs to either 

DbType.String or DbType.Binary 

Leave Trailing Spaces If set, disable the automatic trailing of 

spaces done in a varchar column 

User ID, UID Login account. 

false 

false

Data Server Provider for .NET connection attributes 

Table 8-4 lists the most common connection attributes that Data Server Provider 

for .NET uses. 

Table 8-4 Data Server Provider for .NET connection string attributes 

Attribute Description Default Value 

ConnectTimeout, 

Connect Timeout 

The time (in seconds) to wait for the 

database connection to be established. 

Connection Lifetime Time in seconds that a connection is 

allowed in the pool. 

Database, DB Database to connect to. 

Enlist Enables or disables automatic enlistment 

in a distributed transaction. 

Max Pool Size Maximum number of connections 

allowed in the pool. 

Min Pool Size Minimum number of connections allowed 

in the pool. 

Password, PWD Password associated with the User ID 

Persist Security Info If set the security-sensitive information, 

such as the password, is returned as part 

of the connection string. 

Pooling Enable Connection Pooling within the 

.NET Provider 

Query Timeout Time to wait for an SQL query response 5 

Server Name or alias of the Informix server 

followed by service name or the port 

number 

User ID, UID Login account 

The configuration parameters for Data Server Provider for .NET and most of the 

components are stored in the db2sdriver.cfg file. For a complete list of the 

configuration parameters in this file, refer to: 

http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.swg.im.dbcli 

ent.config.doc/doc/c0054698.html 

If the connection string does not contain all the required information, the provider 

takes the missing arguments from the db2sdriver.cfg configuration file. 

Chapter 8. Working with .NET data providers 261 

0 

60 

true 

0 

0 

false 

true

The majority of the connection string attributes of Data Server Provider for .NET 

have similar meanings and format as Informix .NET Provider string attributes 

except the Server attribute. 

For Informix .NET Provider, the Server keyword contains the name (or alias) of 

the Informix server, which is normally the same as the value of the 

INFORMIXSERVER variable. 

For Data Server Provider for .NET, the Server keyword contains the host name 

where the Informix server is running and the service name or port number that is 

used to listen for DRDA client connections. 

Example 8-5 shows the Server attribute format. In this example, we connect to 

an Informix database server that is running in a system named kodiak.ibm.com. 

The Informix server DRDA alias is using the port number 9089. 

Example 8-5 Server attribute for the Data Server Provider for .NET 

C:\work>connect 

"Server=kodiak.ibm.com:9089;Database=stores_demo;UID=informix;password=password 

;" 

Connected 

Server Type: IDS/NT64, Server Version: 11.50.0000 

Database: STORES_DEMO 

C:\work> 

8.3.2 Data type mapping 

The data types that are used by the .NET Framework differ from the data types 

that are used by the IBM Informix database. In this section, we describe the 

optimal data types to use when accessing data in an Informix database. The 

optimal data type depends on the .NET method that is used to access the data. 

You can use types other than those that we describe here. For example, you can 

use the IfxDataReader.GetString method to obtain any Informix data type. The 

types that we mention here are the most efficient and least likely to change in 

value in data conversion. 


Informix .NET type mapping 

Table 8-5 shows the mapping for the specific IBM Informix data types. 

Table 8-5 Type mapping for Informix specific data 

Informix data type For data reader For data set 

BIGINT Int64 Int64 

BIGSERIAL Int64 Int64 

BLOB IfxBlob Byte[] 

BOOLEAN Boolean Boolean 

BYTE Byte[] Byte[] 

CLOB IfxClob Byte[] 

COMPLEX (ROW, LIST) String String 

DECIMAL(p

Data Server Provider for .NET type mapping 

Table 8-6 shows the type mapping with the Data Server Provider for .NET when 

using specific Informix data types. 

Table 8-6 Type mapping for Informix specific data 

Informix data type Optimal for data reader Optimal for data set 

LVARCHAR IfxString String 

BLOB, BYTE IfxBlob Byte[] 

CLOB, TEXT IfxClob String 

BOOLEAN, SMALLINT IfxInt16 Int16 

BIGINT, BIGSERIAL, INT8, 

SERIAL8 


This section describes the main classes in the Informix .NET Provider and 

demonstrates how to use these classes with basic examples. 

IfxConnection 

The IfxConnection object represents a unique connection with the database 

server. You can specify the connectivity details about the database when creating 

the connection object or by setting the ConnectionString property later. 

Because Informix .NET Provider uses native resources (that are not managed by 

the .NET CLR), always close or dispose any open IfxConnection class when it is 

not longer needed. 


IfxInt64 Int64 

DECIMAL(p

Table 8-7 lists the public method of the IfxConnection class. 

Table 8-7 IfxConnection public methods 

We described the connection string attributes in 8.3.1, “Connecting to the 

database” on page 259. Example 8-6 demonstrates how to connect to the 

database 

Example 8-6 The connect_sample.cs sample 

using System; 





} 

Method Description 

void Open() Opens a database connection 

void Close() Closes the connection to the database 

void ChangeDatabase(String) Changes the current database 

void EnlistTransaction() Enlists the connection in a DTC transaction 

IfxTransaction BeginTransaction() 

BeginTransaction(IsolationLevel) 

} 


Begins a database transaction 

IfxCommand CreateCommand() Creates an instance of an IfxCommand object that 

is associated with this IfxConnection 

IfxBlob GetIfxBlob() Creates an instance of an IfxBlob object that is 

associated with this connection 

IfxClob GetIfxClob() Creates an instance of an IfxClob object that is 

associated with this connection 

try { 

conn = new IfxConnection("Server=demo_on;database=stores_demo"); 

conn.Open(); 

Console.WriteLine("Connected to "+conn.Database); 

conn.Close(); 

} 



} 


Example 8-7 shows the output of Example 8-6. 

Example 8-7 Output of the connect_sample.cs sample 

C:\work>csc.exe /R:%INFORMIXDIR%\bin\netf20\IBM.Data.Informix.dll /nologo 

connect_sample.cs 

C:\work>connect_sample 

Connected to stores_demo 

C:\work> 

IfxCommand 

The IfxCommand object represents an SQL statement or stored procedure to 

execute against a database server. 

Table 8-8 shows methods that the IfxCommand class provides for executing an 

SQL statement. 

Table 8-8 IfxCommand public methods 


Int32 ExecuteNonQuery() Executes an SQL statement against the 

IfxConnection object 

IfxDataReader ExecuteReader() 

ExecuteReader(DataCommandBehavior 

behavior) 


Executes the command in the 

CommandText property against the 

IfxConnection object and builds an 

IfxDataReader object 

Object ExecuteScalar() Executes the query, and returns the first 

column of the first row 

void Cancel() Attempts to cancel the execution of a 

command 

IfxParameter CreateParameter() Creates a new instance of an 

IfxParameter object 

void Prepare() Creates a prepared (or compiled) version 

of the command against the database

Example 8-8 demonstrates how to run a simple DELETE SQL statement. 

Example 8-8 The command_sample.cs sample 

using System; 





} 

} 


int drows=0; 

try { 


conn.Open(); 

IfxCommand cmmd = conn.CreateCommand(); 

cmmd.CommandText = "DELETE FROM customer WHERE customer_num = 103"; 

drows = cmmd.ExecuteNonQuery(); 

Console.WriteLine("Deleted rows: "+drows.ToString()); 

conn.Close(); 

} 



} 

Example 8-9 shows the output of Example 8-8. 

Example 8-9 Output of the command_sample.cs sample 


command_sample.cs 

C:\work>command_sample 

Deleted rows: 1 

C:\work> 

IfxDataAdapter 

The IfxDataAdapter class represents a set of data commands that are used to 

communicate between a data set and the database. A data set is a copy of the 

database data that is stored in memory. 


Table 8-9 lists the methods that the IfxDataAdapter class provides for accessing 

the data. 

Table 8-9 IfxDataAdapter public methods 


Int32 Fill(DataSet) Adds or refreshes rows in the data set 

DataTable FillSchema(DataSet, 

SchemaType) 

IDataParameter 

GetFillParameters() 

Example 8-10 demonstrates how to retrieve data from the database using the 

IfxDataAdapter class. In this example, we retrieve the data rows directly from the 

data set. 

Example 8-10 The dataadapter_sample.cs sample 

using System; 








conn.Open(); 


cmmd.CommandText = "SELECT * FROM state WHERE code='CA'"; 

IfxDataAdapter dadap = new IfxDataAdapter(); 

DataSet dset = new DataSet(); 

dadap.SelectCommand = cmmd; 

dadap.Fill(dset); 

Adds a data table to the data set, and 

configures the schema to match that in the 

database based on the specified SchemaType 

Returns the parameters set by the user when 

executing a SELECT statement 

Int32 Update(DataSet) Executes the SQL statement that is associated 

with the InsertCommand, UpdateCommand, or 

DeleteCommand for each inserted, updated, or 

deleted row in the specified data set 

foreach(DataRow dr in dset.Tables[0].Rows) { 

Console.WriteLine(String.Format("\tCode\tState\n")); 

Console.WriteLine(String.Format("\t{0}\t{1}", dr["code"], dr["sname"]));

} 

} 

} 

conn.Close(); 

Example 8-11 shows the data that is returned by the data set object. 

Example 8-11 Output of the dataadapter_sample.cs sample 


dataadapter_sample.cs 

C:\work>dataadapter_sample.exe 

Code State 

C:\work> 

CA California 

IfxDataReader 

The IfxDataReader class provides fast read-only, forward-only access to a set of 

rows, similar to SQL cursors data. To create an IfxDataReader object, the 

application calls the ExecuteReader() method of the IfxCommand object. 

The IfxDataReader class is a part of the System.Data.Common.DbDataReader. It 

provides all common DbDataReader methods as well as additional methods to 

handle Informix specific data types. 

Table 8-10 contains the additional public methods of the IfxDataReader class. 

Table 8-10 Additional methods of IfxDataReader 


Boolean GetBoolean() Gets the value of the specified column as a Boolean 

TimeSpan GetTimeSpan() Gets the time span value of the specified field 

IfxBlob GetIfxBlob() Gets the IfxBlob value of the specific field 

IfxClob GetIfxClob() Gets the IfxClob value of the specific field 

IfxDateTime GetIfxDateTime() Gets the IfxDateTime value of the specific field 

IfxDecimal GetIfxDecimal Gets the GetIfxDecimal value of the specific field 



IfxMonthSpan GetIfxMonthSpan Gets the IfxMonthSpan value of the specific field 

IfxTimeSpan GetIfxTimeSpan Gets the IfxTimeSpan value of the specific field 

Refer to IBM Informix .NET Provider Reference Guide for a complete list of all the 

IfxDataReader public methods: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.netpr.doc/n 

etpr031023156.htm#netpr031023156 

Note: Even if the IfxDataReader.Read() method returns only one row each 

time it is called, the provider can retrieve more than one row from the 

database. Informix .NET Provider does this to increase performance. The 

application can set the number of rows that the provider fetches from the 

database using the IfxCommand class RowFetchCount property. 

Example 8-12 demonstrates how to use a IfxDataReader class to access a 

database table. 

Example 8-12 The datareader_sample.cs sample 

using System; 








conn.Open(); 


cmmd.CommandText = "SELECT * FROM state WHERE code='CA'"; 

IfxDataReader drdr; 

drdr = cmmd.ExecuteReader(); 

while (drdr.Read()) { 

Console.WriteLine(String.Format("\tCode\tState\n")); 

Console.Write(String.Format("\t{0}", drdr.GetString(0))); 

Console.WriteLine(String.Format("\t{0}", drdr.GetString(1))); 

} 

drdr.Close(); 

conn.Close();

} 

} 


Example 8-13 Output of the datareader_sample.cs sample 


datareader_sample.cs 

C:\work>datareader_sample.exe 

Code State 

C:\work> 

CA California 

IfxError 

The IfxError class collects information that is relevant to a warning or error that 

the database returns. You can use the IfxError and IfxErrorCollection 

classes to retrieve additional information when an error occurs. 

An application can access this information using the properties of the IfxError 

object listed in Table 8-11. 

Table 8-11 IfxError properties 

Property Type Description 

Message String Text message 

NativeError Int32 IBM Informix error code 

SQLState String ANSI SQL error code 

Example 8-14 demonstrates a typical use of the IfxError class. The 

IfxException class contains one or more IfxError objects. 

Example 8-14 The error_sample.cs sample 

using System; 



class Connect { 




} 

} 

int drows=0; 


try { 

conn = new IfxConnection("Server=demo_on;database=wrong_db"); 

conn.Open(); 

Console.WriteLine("Connected"); 

conn.Close(); 

} 

catch (IfxException e) { 

Console.WriteLine("----------------------------"); 

if (e.Errors.Count > 0) { 

IfxError ifxErr = e.Errors[0]; 

Console.WriteLine("Message :" + ifxErr.Message); 

Console.WriteLine("Native error :" + ifxErr.NativeError); 

Console.WriteLine("SQL state :" + ifxErr.SQLState ); 

} 

Console.WriteLine(e.StackTrace); 

Console.WriteLine("----------------------------"); 

} 

IfxParameter 

The IfxParameter class is used to pass parameters to the IfxCommand method. 

IfxParameter classes are stored as a collection in a IfxParameterCollection 

object. 

Table 8-12 contains the public attributes of an IfxParameter object. 

Table 8-12 IfxParameter attributes 


DbType DbType Defines the DbType of the parameter 

Direction ParameterDirection Defines the direction of the parameter 

(Input, Output, or both) 

IfxType IfxType Defines the IfxType class of the 

parameter 

IsNullable Boolean Specifies whether the parameter is 

allowed to be null 

ParameterName String Name of the parameter, which is a unique 

reference in the parameter collection

Example 8-15 shows how to use IfxParameter class to perform an UPDATE 

operation. 

Example 8-15 The parameter_sample.cs sample 

using System; 





} 


SourceColumn String Specifies the column that is mapped to 

the data set 

SourceVersion DataRowVersion Defines the DataRowVersion to use when 

you load Value 

Value Object Defines the value of the parameter 

} 


int urows=0; 

try { 


conn.Open(); 


cmmd.CommandText = "UPDATE state SET sname = ? where code = ?"; 

IfxParameter pcode = new IfxParameter(“code”, DbType.String); 

IfxParameter psname = new IfxParameter(“sname”, DbType.String); 

pcode.Value="CA"; 

psname.Value="CALIFORNIA"; 

cmmd.Parameters.Add(psname); 

cmmd.Parameters.Add(pcode); 

urows = cmmd.ExecuteNonQuery(); 

Console.WriteLine("Updated rows: "+urows.ToString()); 

conn.Close(); 

} 



} 



Example 8-16 Output of the parameter_sample.cs sample 


parameter_sample.cs 

C:\work>parameter_sample.exe 

Updated rows: 1 

C:\work> 

IfxTransaction 

The IfxTransaction class represents an SQL transaction to be made at a 

database. The application creates an transaction by calling the 

BeginTransaction method of the IfxConnection object. 

The IfxConnection.BeginTransaction() method returns an IfxTransaction 

object. When the application decides how to resolve the transaction, it uses the 

Commit and Rollback methods of the IfxTransaction object. 

Any IfxCommand that is involved in a transaction must have the transaction 

property set to the IfxTransaction object. 

Example 8-17 demonstrates how to create a transaction. 

Example 8-17 Creating a transaction using the IfxTransaction class 

using System; 






int drows=0; 


try { 


conn.Open(); 

IfxTransaction trans = conn.BeginTransaction(); 


cmmd.Transaction = trans; 

cmmd.CommandText = "DROP TABLE state"; 

drows = cmmd.ExecuteNonQuery();

} 

} 

trans.Rollback(); 

conn.Close(); 

} 



} 

You can specify the following isolation levels with the BeginTransaction() 

method: 

► ReadUncommitted 

► ReadCommitted 

► RepeatableRead 

► Serializable 

The default Isolation level is ReadCommited. 

Example 8-18 demonstrates how to run a distributed transaction. 

Example 8-18 The transact_cts.cs sample 

using System; 



using System.Transactions; 




try { 


// Transaction options 

TransactionOptions tsopt = new TransactionOptions(); 

tsopt.IsolationLevel = 

System.Transactions.IsolationLevel.RepeatableRead; 

tsopt.Timeout = new TimeSpan(0, 60, 0); 

using (TransactionScope tscope = new TransactionScope( 

TransactionScopeOption.RequiresNew, tsopt, 

EnterpriseServicesInteropOption.Full)) 

{ 

conn.Open(); 




cmmd.CommandText = "DROP TABLE state"; 

cmmd.ExecuteNonQuery(); 

// Rollback the distributed transaction not calling Complete() 

// tscope.Complete(); 

} 

} 



} 

} 

} 

8.3.4 Handling Informix specific data types 

In this section, we discuss how to work with IBM Informix specific data types 

such as smart large objects or decimal using Informix .NET Provider. 

IfxBlob and IfxClob 

CLOB and BLOB are Informix data types that are used to store large amounts of 

character or binary data.The application handles these smart large objects using 

the IfxClob and IfxBlob classes. 

The method that is implemented on these classes allows random access of its 

contents. The application can read or write to certain positions in the large object 

without reading or writing through all of the data up to that position. 

BLOBs and CLOBs are both smart large object type. Both types share many of 

the same methods. BLOBs differ from CLOBs in that the data in a CLOB is 

treated as text characters but the data in a BLOB is not. The data in a BLOB is 

considered to be binary data, and no translation or conversion of any kind is 

performed on it when it is moved to or from the database server. 

Properties and methods 

Table 8-13 lists the IfxBlob and IfxClob public properties. 

Table 8-13 Properties of IfxBlob and IfxClob 


EstimatedSize Int64 Estimates final size of the large object 

ExtentSize Int32 Finds the next extent size for this large object (disk 

space)


Flags Int32 Flags for this large object 

IsNull Boolean Determines whether the large object is NULL 

IsOpen Boolean Determines whether the large object is open 

LastAccessTime Int32 Determines the last time that the large object was 

accessed 

LastChangeTime Int32 Determines the last time that the status was 

changed 

LastModificationTime Int32 Determines the last time that the large object was 

modified 

MaxBytes Int64 Defines the maximum size for the large object 

Position Int64 Defines the current position on the large object 

ReferenceCount Int32 Provides the number of records in the database 

that currently contain a reference to this large 

object 

SBSpace String Defines the Sbspace in which the large object is 

stored 

Size Int64 Defines the size of the large object in bytes 

Table 8-14 lists the available public methods from the IfxClob and IfxBlob 

classes. 

Table 8-14 Public methods of IfxClob and IfxBlob 


void Open(mode) Opens a large object in a specific mode 

IfxSmartLOBLocator GetLocator() Returns the IfxSmartLOBLocator that is 

associated with this instance 

Int64 Read(buff), Read(buff, 

buffOffset, numBytesToRead, 

sLOBOffset, whence) 

Int64 Write(buff), Write(buff, 

buffOffset, numBytesToWrite, 

sLOBOffset, whence) 

Reads the complete data or a portion of a 

large object as a Byte[] or Char[] 

Writes the complete buffer or a portion into 

a large object 

void Truncate(offset) Truncates everything in the large object 

past the position offset 



Int64 Seek(offset, whence) Changes the current position within the 

large object 

void FromFile(filename, appendTosLOB, 

fileLocation) 

String ToFile(filename, mode, 

fileLocation) 

void Lock(sLOBOffset, whence, range, 

lockMode) 

void Unlock(sLOBOffset, whence, 

range) 

Creating a smart large object 

You can use the GetIfxClob() and GetIfxBlob() methods of the 

IfxConnection() object to create a large object. To create a large object: 

1. Create an instance of a the large object, IfxClob or IfxBlob. 

2. Open the large object. 

3. Write data into the large object. 

4. Execute the SQL Statement using the IfxClob or IfxBlob classes as a 

parameter for the statement. 

5. Close the large object. 

Example 8-19 demonstrates how to update a CLOB column. The code reads a 

text file, sample_blob.cs, and uses the contents for the CLOB data. 

Example 8-19 The lo_create.cs sample 

using System; 

using System.IO; 






int urows=0; 

IfxClob vclob; 

char[] vclobBuff; 


Reads an operating system file and writes 

the complete content into the large object. 

Writes the contents of the large object to 

an operating system file 

Locks the complete large object or only a 

portion of the large object 

Unlocks a large object 

void Release() Frees database server resources 

void Close() Closes the large object

try { 

conn = new IfxConnection("Server=demo_on;Database=stores_demo"); 

conn.Open(); 

// Create and Open the Clob 

vclob = conn.GetIfxClob(); 

vclob.Open(IfxSmartLOBOpenMode.ReadWrite); 

// Read a text file and insert into the clob 

vclobBuff = File.ReadAllText("lo_create.cs").ToCharArray(); 

vclob.Write(vclobBuff); 

// Create the UPDATE Ifxcommand 


cmmd.CommandText = "UPDATE catalog set advert_descr = ? WHERE" + 

" catalog_num = ?;"; 

// Bind the IfxClob value and execute the UPDATE statement 

IfxParameter padvt_desc = new IfxParameter(null, vclob); 

IfxParameter pcatalog_n = new IfxParameter(null, "10072"); 

cmmd.Parameters.Add(padvt_desc); 

cmmd.Parameters.Add(pcatalog_n); 



// Close the IfxClob object 

vclob.Close(); 

conn.Close(); 

} 



} 

} 

} 

If the application requires more control over the smart large object, it can use the 

specific properties of the ifxClob and IfxBlob classes to set up values, such as 

in which smart BLOB space the large object should create or the maximum size. 

Example 8-20 Illustrates how to use the properties of the IfxBlob class. 

Example 8-20 Large object extended properties 

... 

// Create and Open the Clob 

vclob = conn.GetIfxClob(); 

vclob.EstimatedSize = 5000; 

vclob.ExtentSize = 1000; 

vclob.Flags = (int) IfxSmartLOBCreateTimeFlags.DontKeepAccessTime | 


... 


(int) IfxSmartLOBCreateTimeFlags.NoLog; 

vclob.MaxBytes = 10000; 

vclob.SBSpace = "sbspace"; 


Selecting a smart large object 

Reading a large object using the large object extensions requires the following 

steps: 

1. Execute the SQL statement, and retrieve the large object column. 

2. Open the large object. 

3. Read from the large object into an application buffer. 

4. Close the large object. 

Example 8-21 shows how to read a large object column from a database table. 

Example 8-21 The lo_select.cs sample 

using System; 







int maxSize = 2000; 

char[] vclobBuff = new char[maxSize]; 

try { 


conn.Open(); 

// Select the large object from the database 


cmmd.CommandText = "SELECT * FROM catalog WHERE catalog_num = 10072"; 



while (drdr.Read()) { 

// Get the large object. The clob is the 6th column 

vclob = drdr.GetIfxClob(5); 

// Open the large object 

vclob.Open(IfxSmartLOBOpenMode.ReadOnly); 

vclob.Read(vclobBuff, 0, maxSize, 0, IfxSmartLOBWhence.Current);

Console.WriteLine(vclobBuff); 

// Close the large object 


} 

} 

} 

conn.Close(); 

} 



} 

Random access 

One of the benefits of smart large objects over a normal large object is the option 

of reading partial data. 

The Read(buff, buffOffset, BytesToRead, loOffset, whence) method allows 

you to position the data pointer anywhere in the large object data and read from 

there. 

Example 8-22 shows how to read the last 10 bytes of a large object. 

Example 8-22 Partial large object read 

... 

// Read only the last 10 bytes of large object 

int bytesToRead = 10; 

vclob.Read(vclobBuff, 0, bytesToRead, (-1) * bytesToRead, 

IfxSmartLOBWhence.End); 

... 

Smart large objects support random I/O access. Using the Seek(offset, 

whence) method, you can position the data pointer anywhere in the large object 

and perform I/O operations with the data. 

Example 8-23 demonstrates how to update only a portion of a large object using 

the Seek() method. 

Example 8-23 A lo_seek.cs sample 

using System; 








int urows=0; 

int maxSize = 100; 

char[] vclobBuff = new char[maxSize]; 

try { 



conn.Open(); 

// Select the large object from the database 


cmmd.CommandText = "SELECT * FROM catalog WHERE catalog_num = 10072"; 



drdr.Read(); 

// Get the large object. The clob is the 6th column 

vclob = drdr.GetIfxClob(5); 

// Open the large object 


// Move the pointer 15 bytes from the beginning of the large object. 

vclob.Seek(15,IfxSmartLOBWhence.Begin); 

// Update the large object. 

vclobBuff="//------------//".ToCharArray(); 

vclob.Write(vclobBuff); 

drdr.Close(); 

// Update the column in the table 

cmmd.CommandText = "UPDATE catalog set advert_descr = ? WHERE" + 

" catalog_num = ?;"; 

// Bind the IfxClob value and execute the UPDATE statement 

IfxParameter padvt_desc = new IfxParameter(null, vclob); 

IfxParameter pcatalog_num = new IfxParameter(null, "10072"); 

cmmd.Parameters.Add(padvt_desc); 

cmmd.Parameters.Add(pcatalog_num); 



// Close the large object 


} 

} 

conn.Close(); 

} 



} 

Note: Data Server Provider for .NET does not support random I/O access.

IfxDateTime 

The IfxDateTime class represents the Informix DATETIME data type. The 

IfxDateTime class provides support for all the precisions that are allowed in an 

Informix DATETIME. 

The Informix DATETIME data type is composed of the following time units: 

► Year 

► Month 

► Day 

► Hour 

► Minute 

► Second 

► Fractions of a second 

In an Informix database, the maximum precision for a DATETIME column is YEAR 

TO FRACTION(5). A DATETIME column can be defined with any precision, from a 

year to fraction of a second allowing any subset of these units. 

Table 8-15 lists the public properties of the IfxDateTime class. 

Table 8-15 Public properties of the IfxDateTime class 


Date IfxDateTime A Year to Day IfxDateTime instance 

Day Int32 The day portion of the value 

EndTimeUnit IfxTimeUnit The end time unit of the instance 

Hour Int32 The hour portion of the value 

MaxValue IfxDateTime Maximum value allowed for this IfxDateTime 

Millisecond Int32 Millisecond unit in this IfxDateTime 

MinValue IfxDateTime Smallest value allowed for this IfxDateTime 

Minute Int32 Minute unit in this IfxDateTime 

Month Int32 Month unit in this ifxDateTime 

Now IfxDateTime Current date with a range of Year to Fraction (5) 

Second Int32 Second unit of this IfxDateTime 

StartTimeUnit IfxTimeUnit Start time unit of this IfxDateTime 

Ticks Int64 Ticks from midnight on 1 Jan 0001 

Today IfxDateTime Current time with a range of Year to Day 



Year Int32 Year unit of the value 

Table 8-16 lists the public methods of the IfxDateTime class. 

Table 8-16 Public methods of the IfxDateTime class 


Add(IfxTimeSpan or IfxMonthSpan) Current value plus by object passed 

AddDays(days) Current value plus days passed 

AddMilliseconds(milliseconds) Current value plus milliseconds passed 

AddMinutes(minutes) Current value plus minutes passed 

AddMonths(months) Current value plus months passed 

AddSeconds(seconds) Current value plus seconds passed 

AddYears(years) Current value plus years passed 

Compare(ifxDT1, ifxDT1) Compare two IfxDateTime instances 

CompareTo(obj) Compare two IfxDateTime instances 

DaysInMonth(year, month) Number of days in the month of the year 

Equals(ifxDT1, ifxDT2) True if ifxDT1 is equal to ifxDT2 

GreaterThan(ifxDT1, ifxDT2) True if ifxDT1 is later than ifxDT2 

GreaterThanOrEqual(ifxDT1, 

ifxDT2) 


True if ifxDT1 is later or equal than ifxDT2 

LessThan(ifxDT1, ifxDT2) True if ifxDT1 is earlier than ifxDT2 

LessThanOrEqual(ifxDT1, ifxDT2) True if ifxDT1 is earlier or equal than ifxDT2 

NotEquals(ifxDT1, ifxDT2) True if ifxDT1 is different than ifxDT2 

Parse(dateTimeStr) 

Parse(dateTimeStr, start, end) 

Parse(dateTimeStr, format, start, 

end) 

New IfxDateTime with a value based on 

dateTimeStr 

ToString(), ToString (format) Value of the instance as a string

To access a DATETIME column in the database, the application uses the 

IfxGetDateTime() method from the IfxDataReader() object. 

Example 8-24 demonstrates how to select a DATETIME data type from a table. 

Example 8-24 The datetime.cs sample 

using System; 






IfxDateTime vdtime; 

try { 


conn.Open(); 

// Select the datetime from the database 


cmmd.CommandText = "SELECT * FROM cust_calls WHERE " 

+ "customer_num = 106"; 



drdr.Read(); 

// Get the IfxDateTime from the recordset, 2nd columnd 

vdtime = drdr.GetIfxDateTime(1); 

Console.WriteLine("Call:\t"+vdtime); 

Console.WriteLine("Hour :\t "+vdtime.Hour); 

Console.WriteLine("Minute:\t"+vdtime.Minute); 

conn.Close(); 

} 



} 

} 

} 

Example 8-25 shows the Hour and Minute units extracted from the IfxDateTime 

object. 

Example 8-25 Output of the datetime.cs sample 


datetime.cs 

C:\work>datetime 

Call: 2008-06-12 08:20 


Hour : 8 

Minute: 20 

C:\work>c 

Arithmetic operations between two IfxDateTime objects might return an 

lfxDateSpan() object or an IfxMonthSpan() object, depending on the precision 

that is used by the IfxDateTime objects. 

Example 8-26 shows the use of the IfxDateSpan() class. 

Example 8-26 The datetime2.cs sample 

using System; 






IfxDateTime vdtime,vrestime; 

IfxTimeSpan vtimetaken; 

try { 



conn.Open(); 



cmmd.CommandText = "SELECT * FROM cust_calls WHERE " 

+ "customer_num = 106"; 



drdr.Read(); 

// Get the IfxDateTime from the recordset 

vdtime = drdr.GetIfxDateTime(1); 

vrestime = drdr.GetIfxDateTime(5); 

// Stores the difference in an IfxTimeSpan object. 

vtimetaken=vrestime-vdtime; 

Console.WriteLine("Initiated at:\t"+vdtime); 

Console.WriteLine("Resolved at:\t"+vrestime); 

Console.WriteLine("Minutes taken:\t"+vtimetaken.Minutes); 

conn.Close(); 

} 



} 

} 

}

IfxDecimal 

An IfxDecimal object represents the Informix decimal data type. The DECIMAL 

data type on an Informix database can take two forms: 

► DECIMAL(p) floating point 

► DECIMAL(p,s) fixed point 

The IfxDecimal object in Informix .NET Provider supports both versions. 

Table 8-17 contains the description of the public properties of an IfxDecimal 

object. 

Table 8-17 Public properties of the IfxDecimal class 


E IfxDecimal Irrational number e 

IsFloating Boolean Whether it is a floating number 

IsNull Boolean Whether it is NULL 

IsPositive Boolean Whether it is positive 

MaxPrecision Byte Maximum precision supported (32) 

MaxValue IfxDecimal Largest value allowed 

MinusOne IfxDecimal -1 

MinValue IfxDecimal Smallest value allowed 

Null IfxDecimal Null 

One IfxDecimal 1 

Pi IfxDecimal Irrational number pi 

Zero IfxDecimal 0 

Table 8-18 contains the description for the IfxDecimal public methods. 

Table 8-18 Public methods of the IfxDecimal object 


Abs(IfxDec) Absolute value of IfxDec 

Add(IfxDec1, IfxDec2) Sum of IfxDec1 and IfxDec2 

Ceiling(IfxDec) Smallest integer that is not less than IfxDec 

Clone() Creates a duplicate of this instance 



Compare(IfxDec1, IfxDec2) Compares two IfxDecimal values 

CompareTo(obj) Compares current instance with object 

Divide(Dividend, Divisor) Dividing result for Dividend by Divisor 

Equals(obj) Equal 

Equals(IfxDec1, IfxDec2) True if IfxDec1 is the same as IfxDec2 

Floor(IfxDec) Largest integer not larger than IfxDec 

GreaterThan(IfxDec1, IfxDec2) True if IfxDec1 > IfxDec2 

GreaterThanOrEqual(IfxDec1,IfxDe 

c2) 


True if IfxDec1 >= IfxDec2 

LessThan(IfxDec1, IfxDec2) True if IfxDec1 < IfxDec2 

LessThanOrEqual(IfxDec1, 

IfxDec2) 

True if IfxDec1

An application uses the GetIfxDecimal() method from the IfxDataReader() 

class to access a DECIMAL column from the database. 

Example 8-27 demonstrates how to retrieve a DECIMAL column 

Example 8-27 The decimal.cs sample 

using System; 






IfxDecimal vtax; 

try { 


conn.Open(); 



cmmd.CommandText = "SELECT * FROM state WHERE " 

+ "code = 'CA'"; 



drdr.Read(); 

// Get the IfxDecimal from the recordset 

vtax = drdr.GetIfxDecimal(2); 

Console.WriteLine("Value Sales Tax :\t "+vtax); 

Console.WriteLine("Ceiling Sales Tax :\t " + IfxDecimal.Ceiling(vtax)); 

Console.WriteLine("Negative Sales Tax :\t " + IfxDecimal.Negate(vtax)); 

conn.Close(); 

} 



} 

} 

} 

Example 8-28 shows the output of the previous example. 

Example 8-28 Output of the decimal.cs sample 

C:\work>csc.exe /R:%INFORMIXDIR%\bin\netf20\IBM.Data.Informix.dll /platform:x86 

decimal.cs 


C:\work>decimal 

Value Sales Tax : 0.0825 

Ceiling Sales Tax : 1.0 

Negative Sales Tax : -0.0825 

C:\work> 


In this section, we discuss typical errors that occur when using the .NET 

providers and how to enable the tracing facility to collect diagnostic information. 

Typical errors 

If the application fails to connect to the Informix database server, verify that 

connection string details are correct for the server and version of the .NET 

provider that you are using. 

Both .NET providers use the ODBC or CLI layer to communicate with the 

database server. You can test the connection with these components before 

using a .NET provider. 

When using Informix .NET Provider, always test the connectivity first using the 

iLogin utility that is included with Client SDK. 

Data Server Provider for .NET includes the Testconn11.exe and Testconn20.exe 

executables that you can use to diagnose connectivity and setup problems when 

using Data Server Provider for .NET. 

Table 8-19 lists typical errors and how to resolved them. 

Table 8-19 Typical errors 

Error Reason Solution 

ERROR [IM009] [Informix .NET 

provider] 

Unable to load translation 

shared library (DLL) 

System.BadImageFormatExcepti 

on: An attempt was made to 

load a program with an 

incorrect format 


The Informix .NET Provider 

failed to load the ODBC 

shared library. 

A 32-bit application is 

attempting to load a 64-bit 

IBM.Data.Informix 

assembly. 

Verify that the values for the 

INFORMIXDIR environment variable 

and PATH are correct. 

INFORMIXDIR should point to the 

Client SDK installation directory, and 

PATH should contain the 

%INFORMIXDIR%\bin directory. 

Register the proper version of the 

.NET assembly into the GAC using 

the gacutil.exe tool.

Error Reason Solution 

Unhandled Exception: 

System.EntryPointNotFoundExc 

eption: Unable to find an 

entry point named 

'InterlockedIncrement' in DLL 

'kernel32.dll'. 

Unhandled Exception: 

System.DllNotFoundException: 

Unable to load DLL 

'IfxDotNetIntrinsicModule.dl 

l': The specified module 

could not be found. 

8.3.6 Tracing 

Your application can set the following types of tracing when using Informix .NET 

Provider: 

► Informix .NET Trace 

► SQLIDEBUG 

Informix .NET Trace 

This trace is specific to Informix .NET Provider. To use this feature, the 

application must use the Trace version of the IBM.Data.Informix assembly 

located in the %INFORMIXDIR%\netf20 directory. The name of shared library is 

IBM.Data.Trace.dll. 

Register the assembly in the GAC and enable the trace by setting the 

IFXDOTNETTRACE and IFXDOTNETTRACEFILE environment variables. 

Example 8-29 demonstrates how to register the trace library and generate a 

.NET trace file. 

Example 8-29 Trace setup 

C:\work>gacutil /i %INFORMIXDIR%\bin\netf20\IBM.Data.IfxTrace.dll /nologo 

Assembly successfully added to the cache 

C:\work>set IFXDOTNETTRACE=2 

A 64-bit application is 

attempting to load a 32-bit 

IBM.Data.Inforimx.dll 

assembly. 

Failed to load 

IfxDotNetIntrinsicModule 

assembly that is required by 

the 64-bit version of Informix 

.NET Provider. 

C:\work>set IFXDOTNETTRACE=trace.txt 

C:\work>decimal 

Value Sales Tax : 0.0825 

Register the proper version of the 

.NET assembly into the GAC using 

the gacutil.exe tool. 

When using the 64-bit version of 

Informix .NET Provider, the PATH 

environment variable needs to define 

the %INFORMIXDIR%\bin and 

%INFORMIXDIR%\bin\netf20 

directories. 


Ceiling Sales Tax : 1.0 

Negative Sales Tax : -0.0825 

C:\work>dir trace.txt 



Directory of C:\work 

25/06/2010 13:52 13,172 trace.txt 



C:\work> 

The .NET trace file contains information about all the .NET classes that are used 

and their return values. Example 8-30 shows some of the entries in the .NET 

trace file. 

Example 8-30 .NET Trace file 

... 

3532:1 Entry: IfxDecimal.ToString() 

3532:1 Exit: IfxDecimal.ToString 

IfxDecimal 0.0825 

3532:1 Entry: IfxDecimal.ToString() 

532:1 Exit: IfxDecimal.ToString 

IfxDecimal -1.0 

) 

3532:1 Entry: IfxDecimal.get_IsNull() 

3532:1 Exit: IfxDecimal.get_IsNull 

532:1 Exit: IfxDecimal.Multiply 

3532:1 Exit: IfxDecimal.Negate 

3532:1 Entry: IfxConnection.Close() 

3532:1 Entry: IfxConnection.GetLatch 

( 

String IfxConnection.Close 

) 

... 


The level of tracing is determine by the value of the IFXDOTNETTRACE variable: 

0 No tracing 

1 Tracing of API entry and exit, with return code 

2 Tracing of API entry and exit, with return code, plus tracing of parameters 

to the API 

Levels 3 and 4 are for internal use only. 

SQLIDEBUG and DRDADEBUG 

Refer to “SQLIDEBUG” on page 119 for the description and use of the 

SQLIDEBUG. 

8.4 Visual Studio Add-In for Visual Studio 

This section gives an overview of Visual Studio Add-in. The IBM Database 

Add-Ins for Visual Studio are a collection of features that integrate into Microsoft 

Visual Studio development environment so that you can work with IBM data 

servers. 

Visual Studio Add-in Version 9.5 is compatible with Visual Studio 2005, and it 

uses Informix .NET Provider to connect to the database server. 

Version 9.7 is compatible with Visual Studio 2005 and Visual Studio 2008 and 

uses Data Server Provider for .NET. 

Although it is not included in the Client SDK bundle, Visual Studio Add-in is 

available as a separate product. For more information, refer to: 

https://www.software.ibm.com/webapp/iwm/web/reg/download.do?source=swg-vsai 


Visual Studio Add-In provides tools and wizards that simplify the .NET 

development for the following common tasks: 

► Explore catalog information of the database server. 

► Generate Data Definition Language (DDL) for database objects. 

► Drag server objects onto .NET application components to generate the 

required ADO.NET code automatically. 

To use Visual Studio Add-In, you first define the Informix server in the Data 

Connections group of the Visual Studio environment. Select the Add Connection 

to add a new server definition. 

In the Add Connection panel, specify the server name, server log on ID and 

password, and the database name. 

When the database is connected, you can drag the Informix tables from the 

Server Explorer pane to the .Net data set pane. 

For more details about using IBM Database Add-Ins and Data Server Provider 

for .NET for application development, refer to the IBM Information Management 

and Visual Studio .NET zone at: 

http://www.ibm.com/developerworks/data/zones/vstudio 


Chapter 9. Working with PHP 

PHP is a powerful server-side scripting language that was invented and that is 

designed for creating dynamic web applications with non-static content. The PHP 

code can be a stand-alone program or an insert inside Hypertext Markup 

Language (HTML) or Extensible Hypertext Markup Language (XHTML). The 

PHP syntax is based mostly on and is similar to the C, Java, and Perl 

programming language. You can use PHP based on an open-source license. 

This chapter discusses the use of PHP with Informix as the database server. We 

discuss various PHP database extensions that you can use to connect to 

Informix. We also discuss other components, such as Apache Web Server and 

OpenAdmin Tool (OAT), and how to bring these components together. We 

describe in detail the use of programming interfaces that are provided by 

selected PHP database extensions through the use of various examples. 


► Informix and PHP extensions 


► Developing a PHP application 

9 


9.1 Informix and PHP extensions 

The PHP Data Objects (PDO) extension defines a lightweight, consistent 

interface for accessing databases in PHP. Each database driver that implements 

the PDO interface can expose database-specific features as regular extension 

functions. 

Informix database can be accessed by PHP using the following PDO drivers: 

► PDO_INFORMIX 

This driver is also called PHP Driver for IBM Informix. To compile and use 

the driver, you must install Informix Client Software Development Kit (Client 

SDK). You can download this driver from: 

http://pecl.php.net/package/PDO_INFORMIX 

► PDO_IBM 

This driver is also know as PHP Driver for Data Server clients. To use this 

driver, you must install IBM Data Server Driver for ODBC and CLI on the 

same computer. You can download this from: 

http://pecl.php.net/package/PDO_IBM 

In addition to these two drivers, the following PHP extensions allow you to access 

an IBM Informix database: 

► PHP_INFORMIX 

This extension provides support only for standard Informix data types. This 

extension is developed by the open source community and is available at: 

http://cvs.php.net/viewvc.cgi/pecl/informix/ 

► IBM_DB2 

This extension is available with IBM Data Server Driver and is written, 

maintained, and supported by IBM. It supports the Informix and DB2 

databases. 

Your application development environment, including hardware and software, 

determines which PHP drivers and extensions to use. If the platform of your 

choice is not supported by IBM Data Server Driver or if you are using some of the 

data types that are not supported by IBM Data Server Driver, then use the 

Informix driver. The Data Server Driver for ODBC and CLI requires an Informix 

database of Version v11.x or later. If your database server is exclusively Informix, 

then you can use the Informix driver. You can also use both drivers 

simultaneously if needed. 



9.2.1 Installing OAT 

To develop a PHP application for Informix, your application development system 

must have the following software: 

► PHP drivers and extensions 

Choose one of the PHP drivers or extensions that Informix supports. The 

PHP Driver for IBM Informix requires Client SDK and the PHP Driver for Data 

Server clients requires the IBM Data Server Driver for ODBC and CLI. Refer 

to 2.2, “Client setup” on page 34 for the details. 

► Web server 

You can either install Apache Web Server or use OpenAdmin Tool (OAT), 

which is a PHP-based web browser administration tool. Installing OAT is an 

easier option, because it contains everything that is required for PHP 

connectivity. At the time of writing this book, OAT version 2.2.7 has the 

following components: 

– Apache 2.2.4 

– PHP 5.2.4 

– PDO_INFORMIX 1.2.6 

In this section, we discuss OAT installation and driver configuration. For 

information about how to install the latest Apache Web Server, refer to the 

following website: 

http://httpd.apache.org/ 

OpenAdmin Tool (OAT) is available for Windows, Linux, and Macintosh OS X 

(64-bit only) at: 

http://www.openadmintool.org 

This website leads you to the IBM site, where you must register and log in. 

After you complete the download, the installation procedure is as follows: 

1. Start the installation with one of the following methods: 

– GUI mode 

Launch the installation executable using one of the following commands: 

On Windows systems: Run install.exe. 

On Linux: Run install.bin. 

On MAC OS X: Extract the install.zip file, and run install.app. 

Chapter 9. Working with PHP 297

– Console mode 

Enter one of the following commands: 

On Windows systems: install.exe -i console 

On Linux: install.bin -i console 

2. Accept the license agreement to continue. 

3. Select the installation directory. The default directory is as follows: 

– For Windows systems: C:\Program Files\OpenAdmin 

– For Linux: /opt/OpenAdmin 

– For MAC OS X: /Applications/OpenAdmin/ 

4. Choose an available port number for the web server. 

5. For Windows operating system users, provide an Apache service name. 

6. Specify the host name, which is the name of the computer where the 

database server is located. 

7. In the Security Features panel, enable password-protection for OAT 

administration pages. 

8. In the OAT Administrator login setup panel, enter a user name and password. 

9. In the Plug-in page, ensure that the plug-ins that you want to install are 

selected. Accept the license agreement. 

10.In the Pre-Installation Summary panel, review your selections and proceed 

with the installation. When the installation is complete, the following message 

displays: 

OpenAdmin Tool has been installed successfully. Please visit 

http://servername:portnumber/openadmin/ to use the OpenAdmin Tool 

Where: 

– servername is the name of the system where the web server is running. 

This name can be localhost on Windows. 

– portnumber is the port number that you provided in step 4. 

11.Click Done. 

– For Windows systems: You need to reboot. You can access OAT from the 

Start � All Programs � OpenAdmin Tool for IDS. 

– For Linux and MAC OS X: The OAT configuration page opens in your 

default web browser. 

For an insight into OAT, read the release notes and the README file that are 

bundled with the product. 


9.2.2 Verifying the PDO_INFORMIX setup 

We discuss the installation of the PDO_INFORMIX driver in 2.2.3, “Setting up 

IBM Data Server drivers” on page 43. The PDO_INFORMIX driver is installed 

automatically when you install OAT. 

We use the PDO_INFORMIX driver and the Apache Web Server that is installed 

with OAT in a Windows system for the examples in this chapter. 

On successful installation of OAT, the php_pdo_informix.ddl shared library (.so 

extension in Linux) is placed in the PHP extension directory. For example, if your 

installation directory is C:\Program FIles\OpenAdmin, the shared library is in the 

C:\Program Files\OpenAdmin\PHP_5.2.4\ext directory. 

To verify that the PHP extensions are working, enter the following URL in a web 

browser: 

http://localhost:8080/phpinfo.php 

9.2.3 Verifying the PDO setup 

We discuss the installation of the PDO_IBM driver in 2.2.3, “Setting up IBM Data 

Server drivers” on page 43. Depending on your platform copy, add the .dll or 

.so to the OAT extension directory and change the php.ini to include the 

extension php_pdo_ibm.dll or php_pdo_ibm.so. 

You can see which PDO driver is loaded by the Apache Web Server by typing the 

following address in your browser: 

http://localhost:8080/phpinfo.php 



You can use a simple PHP program to verify the connectivity to the Informix 

server using the installed Informix PHP drivers or extensions. 

Example 9-1 shows a simple PHP script that connects to the database server 

using the PDO_INFORMIX driver. In the conn_string variable, set the proper 

host name, user name, password, and respective locales. The first keyword in 

the connection string identifies the PDO driver that is used. The 

PDO_INFORMIX driver uses informix, and the PDO_IBM driver uses ibm. 

Example 9-1 The connect.php program 

You can use the same script to test the connectivity using the PDO_IBM driver by 

just changing the connection string. Example 9-2 shows a typical connection 

string using the PD_IBM driver. 

Example 9-2 PDO_IBM connection string 

$conn_string = "ibm: DRIVER={IBM DB2 ODBC 

DRIVER};DATABASE=stores_demo;HOSTNAME=kodiak;PORT=9089;PROTOCOL=TCPIP;"; 

At this point, you know that your environment is set up properly, and you are 

ready to begin using PHP with Informix. 

9.3 Developing a PHP application 

PHP is a powerful, server-side scripting language that was invented and 

designed for creating dynamic web applications with non-static content. The PHP 

code can be a stand-alone program or an insert inside Hypertext Markup 

Language (HTML) or Extensible Hypertext Markup Language (XHTML). The 

PHP syntax is based mostly on and similar to C, Java, and Perl. You can use 

PHP with an open-source license. You can run the PHP program directly from the 

command line. 

We chose PHP for our applications for the following reasons: 

► Easy to use 

PHP is a scripting language that is included directly in HTML. Thus, getting 

started is easy. There is no need to compile PHP programs or spend time 

learning tools to create PHP. You can simply insert statements and get quick 

turnaround as you make changes. 

► Fully functional 

The PHP language has built-in functions to access your favorite database. 

With PHP, your HTML pages can reflect current information from databases. 

You can use information for the user who is viewing your HTML web page to 

customize the page specifically for that user. You can create classes for 

object-oriented programming or use flat file or Lightweight Directory Access 

Protocol (LDAP) databases. It also includes a spelling checker, XML 

functions, image generation functions, and more. 

► Compatible and quick 

Because PHP generates plain HTML, PHP is compatible with all web 

browsers. 


► Secure 

Although PHP is open source, it is a secure environment. Web clients can 

only see the pure HTML code. The logic of the PHP program is never 

exposed to the client; therefore, security exposures are reduced. 

► Open source 

PHP is an open-source programming language. It is easy to get started and 

find examples from websites. For example: 

http://www.sourceforge.net 

9.3.1 Connecting to a database 

Regardless of which PHP driver you use, PDO_INFORMIX or PDO_IBM, you 

must decide the type of connection to use for any database connection and the 

user type to use for authentication. 

Connection type 

The following connection type behavior is controlled by the web server: 

► Persistent connection 

For the persistent connection, the web server leaves the connection to the 

database open after the PHP script completes its work. The next attempt to 

connect to the database with the same parameters reuses the connection. 

► Standard connection 

For the standard connection, the database connection is closed when the 

script completes its execution. 

Here are some considerations for persistent connection: 

► When using the persistent connection, the same connection is used for the 

next request with the same connection parameters. This connection might 

cause connection pooling, depending on the implementation and how you 

decide whether the connection is reused. Unintentional connection pooling is 

most likely a source of serious problems, even if you use transactions. 

► Opening up a persistent connection makes sense only in a web server 

environment if the connection is not closed in the same script with a 

connection close call. Calling the PHP command line processor on the shell 

closes the connection to the Informix database server at the end of the 

execution of the script. 


► The web server spawns more than one process to handle the incoming web 

requests. So, reusing the existing persistent connection is valid only for a 

specific web server process. It results in the database server having more 

connections open than actual running web server processes. 

► Restarting the database server without cleaning up the remaining persistent 

connections in the web server environment produces no errors at connection 

time when the connection is reused but fails at the first database statement. 

This type of error is hard to diagnose. 

The user type 

The user type is controlled by the database and has to do with authentication at 

the database server. You can choose an authentication with user ID and 

password in the connection string or a trusted user connect where the database 

server does not apply an authentication. This connection is controlled by settings 

on operating system resources, such as .rhosts or /etc/hosts.equiv files. 

Because you have to specify user names and passwords in the PHP scripts, pay 

attention to these files in regard to security. Use encapsulation for files that 

contain passwords, and put these files in directories that are secured with the 

.htaccess or httpd.conf mechanism of the Apache Web Server. 

Informix PDO requires, at connection time, a defined set of parameters: 

► Database name 

► Database server name 

We suggest that you use a user ID and password for untrusted user sessions. 

Some optional parameters can influence the cursor behavior. In this section, we 

focus on the required connection parameters. 

Example 9-3 gives an overview about the various parameter settings in an 

attempt to connect to the Informix database server. The examples shown are for 

the PDO_INFORMIX driver. Choose one of the connection statements that 

meets your requirements. 

Example 9-3 The PDO_INFORMIX driver connection strings 

/*--- standard connect ---*/ 

$dbc = new PDO("informix:; database=sysmaster; 

server=ol_svr_custom;","informix", "123456"); 

/*--- standard connect trusted user ---*/ 

$dbc = new PDO("informix:; database=sysmaster; server=ol_svr_custom;"); 

/*--- persistent connect untrusted user ---*/ 


server=ol_svr_custom;","informix","123456",array(PDO::ATTR_PERSISTENT=> true)); 


*--- persistent connect trusted user ---*/ 


server=ol_svr_custom;",NULL,NULL,array(PDO::ATTR_PERSISTENT=> true)); 

The PDO_IBM driver is based on the Data Server Driver CLI driver. Thus, it uses 

the same connectivity information as the ODBC and CLI driver. You can store this 

information, as well as user credentials, in the db2cli.ini file that is located in 

the user profile directory. Example 9-4 shows an example db2cli.ini file. 

Example 9-4 An example db2cli.ini file 

[dsc_dsn] 


Port=9089 



PWD=password 

UID=password 

Having the details inside the db2cli.ini file makes it easier to manage the 

information that is needed for the connection. You can use either of the 

connection strings mentioned in the Example 9-5. The second conn_string uses 

the dbscli.ini file shown in Example 9-4 on page 304. 

Example 9-5 PDO_IBM connection strings 

$conn_string = "ibm: DRIVER={IBM DB2 ODBC DRIVER};DATABASE=stores_demo; 

HOSTNAME=kodiak;PORT=9089;PROTOCOL=TCPIP;"; 

$conn_string = "ibm: DSN=dsc_dsn"; 


Informix supports both static and dynamic SQL statements for the client 

applications such as PHP programs. In this section, we provide an in-depth 

discussion about the abilities of handling dynamic and static SQL of PDO 

Informix. We focus on the INSERT statement but also give short examples for the 

DELETE and UPDATE statements. 


Static SQL statements 

Example 9-6 shows various methods to execute a static INSERT with Informix 

PDO. 

Example 9-6 INSERT, UPDATE, and DELETE using the PDO_INFORMIX driver 

In a web application, the input data frequently comes from an HTML form that is 

entered by a web user. Example 9-7 shows, based on a simple HTML form, how 

the data flows from the HTML over the PHP script into the database table. 

Example 9-7 HTML sample 

basic html format 

 

Example 9-8 shows the PHP script that handles the HTML form. The $_POST 

array contains all the settings for the buttons and the values for the text fields 

from the HTML. 

Example 9-8 PHP Script handling the insert 

$dbc->query($statement); 

$error=$dbc->errorInfo(); 

if ( $error["1"]) { 

printf(" prepare insert failed with %s \n",$error["1"]); 

exit(1); 

} 

?> 

Example 9-9 shows how to perform an update and a delete using the PDO 

Informix extension. 

Example 9-9 Update a PHP script 

Dynamic SQL statements 

Dynamic SQL statements allow an Informix client side program to build an SQL 

statement at run time, so that the content of the statement can be determined by 

user input. Informix PDO provides several methods to use dynamic SQL. You 

must use placeholders, such as “?” or “:parameter” to prepare a statement for 

dynamic usage. These placeholders are later substituted with the values. 

The “prepare once, execute multiple times” capability of dynamic statements 

allows you to specify different values at each execution time. To determine which 

statements and clauses allow placeholders, refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.sqls.doc/sqls 

.htm 

This document also provides a comprehensive reference of Informix SQL 

statements. 

Example 9-10 shows different INSERT statements using Informix PDO. To learn 

more about using placeholders (“?”) and bind parameters, refer to PHP manual 

at: 

http://php.net/manual/en/pdostatement.bindparam.php 

Example 9-10 INSERT statements using Informix PDO 

printf(" prepare insert2 failed with %s \n",$error["1"]); 

exit(1); 

} 

/*--- dynamic inserts with : placeholders and bindParam ---*/ 

$stmt= 

$dbc->prepare("INSERT INTO customer VALUES (0,:p1,:p2,:p3,:p4,:p5,:p6,:p7,:p8,:p9)"); 

$stmt->bindParam(':p1', $_POST["fname"]); 

$stmt->bindParam(':p2', $_POST["lname"]); 

$stmt->bindParam(':p3', $_POST["company"]); 

$stmt->bindParam(':p4', $_POST["address1"]); 

$stmt->bindParam(':p5', $_POST["address2"]); 

$stmt->bindParam(':p6', $_POST["city"]); 

$stmt->bindParam(':p7', $_POST["state"]); 

$stmt->bindParam(':p8', $_POST["zipcode"]); 

$stmt->bindParam(':p9', $_POST["phone"]); 

$stmt->execute(); 


if ( $error["1"]) { 


exit(1); 

} 

/*--- dynamic inserts with "?" placeholders and bindValue ---*/ 

$stmt= 

$dbc->prepare("INSERT INTO customer VALUES (99,?,?,?,?,?,?,?,?,?)"); 

$stmt->bindValue(1, $_POST["fname"],PDO::PARAM_STR); 

$stmt->bindValue(2, $_POST["lname"],PDO::PARAM_STR); 

$stmt->bindValue(3, $_POST["company"],PDO::PARAM_STR); 

$stmt->bindValue(4, $_POST["address1"],PDO::PARAM_STR); 

$stmt->bindValue(5, $_POST["address2"],PDO::PARAM_STR); 

$stmt->bindValue(6, $_POST["city"],PDO::PARAM_STR); 

$stmt->bindValue(7, $_POST["state"],PDO::PARAM_STR); 

$stmt->bindValue(8, $_POST["zipcode"],PDO::PARAM_STR); 

$stmt->bindValue(9, $_POST["phone"],PDO::PARAM_STR); 



if ( $error["1"]) { 


exit(1); 

} 

/*--- dynamic inserts with : placeholders and bindValue ---*/ 

$stmt= 

$dbc->prepare("INSERT INTO customer VALUES 

(199,:p1,:p2,:p3,:p4,:p5,:p6,:p7,:p8,:p9)"); 

$stmt->bindValue(':p1', $_POST["fname"],PDO::PARAM_STR); 

$stmt->bindValue(':p2', $_POST["lname"],PDO::PARAM_STR); 

$stmt->bindValue(':p3', $_POST["company"],PDO::PARAM_STR); 

$stmt->bindValue(':p4', $_POST["address1"],PDO::PARAM_STR); 

$stmt->bindValue(':p5', $_POST["address2"],PDO::PARAM_STR); 

$stmt->bindValue(':p6', $_POST["city"],PDO::PARAM_STR); 

$stmt->bindValue(':p7', $_POST["state"],PDO::PARAM_STR); 

$stmt->bindValue(':p8', $_POST["zipcode"],PDO::PARAM_STR); 


$stmt->bindValue(':p9', $_POST["phone"],PDO::PARAM_STR); 



if ( $error["1"]) { 

printf(" prepare4 insert failed with %s \n",$error["1"]); 

exit(1); 

} 

?>l 

9.3.3 Handling complex data types 

In this section, we discuss how to use complex data types in a PHP program. We 

cover row types, collection types (such as SET, LIST, and MULTISET), and the 

BLOB and SBLOB data types. We explain how to work with the complex data 

types using examples with Informix PDO. 

Named row types 

Example 9-11 shows the Data Definition Language (DDL) to create a ROW type 

and the table that uses the ROW type. 

Example 9-11 DDL for creating ROW type and table 

/*Create a row type and a table by name customer_rtype as below 

CREATE ROW TYPE address_rtype ( 

street_num int, 

street_name char(20), 

city char(20), 

state char(20), 

zipcode char(10) 

); 

CREATE TABLE customer_rtype ( 

customer_num serial, 

lname char(15), 

fname char(15), 

company char(20), 

address address_rtype, 

phone char(18) 

); 


The PHP script in Example 9-12 shows SQL statements using ROW type. This 

script inserts two rows and selects the data from the database with and without a 

filter on the row type. It then updates one of the rows and delete the rows from 

the table. 

Example 9-12 Insert complex types sample 

*--- Verification ---*/ 

$stmt1=$dbc->query(' SELECT customer_num,fname, address::lvarchar FROM customer_rtype 

WHERE address = row(1234,"Almeda blvd","Fremont","CA","12345")::address_rtype'); 

$row=$stmt1->fetch(PDO::FETCH_ASSOC); 

while($row) { 

print_r($row); 

printf(""); 


} 

printf(" [ DELETE ] "); 

/*--- close the buisness ---*/ 

$dbc->query(' DELETE FROM address_rowtype '); 

$dbc->query(' DELETE FROM customer_rtype '); 

?> 

Example 9-13 shows the output from the SELECT statements to give you an idea 

of how the array with row types looks in PHP. 

Example 9-13 Output of ROW type example 

[ INSERT ] 

[ SELECT without row_type filter ] 

Array ( [CUSTOMER_NUM] => 1 [FNAME] => Gomes [CITY] => San Fransisco [STATE] => CA 

[PHONE] => 408-908-8887 ) 

Array ( [CUSTOMER_NUM] => 2 [FNAME] => jones [CITY] => Fremont [STATE] => CA [PHONE] => 

345-908-8887 ) 

[ SELECT with filter ] 

Array ( [CUSTOMER_NUM] => 2 [STATE] => CA [PHONE] => 345-908-8887 ) 

[ UPDATE ] 

[ SELECT ] 

Array ( [CUSTOMER_NUM] => 2 [FNAME] => jones [] => ROW(1234 ,'Almeda blvd ','Fremont 

','CA ','12345 ') ) 

[ DELETE ] 


Collection data types 

The collection data types are another set of complex data types provided by the 

Informix. Collection data types include SET, LIST, and MULTISET. In this section, 

we cover these collection data types. Example 9-14 shows an example that 

inserts into and selects from a table containing collection data types. 

Example 9-14 Using collection data types in PHP 


while($row) { 

print_r($row); 

printf(""); 


} 

?> 


Example 9-15 The output of collection data type 

[ Insert ] 

[ SELECT without filter] 

Array ( [LIST] => LIST{-1 ,0 ,-2 ,3 ,0 ,0 ,32767 ,249 } [SET] => SET{-1 ,0 ,-2 

,3 } [MULTISET] => MULTISET{-1 ,0 ,0 ,-2 ,3 ,0 } ) 


,3 } [MULTISET] => MULTISET{-1 ,0 ,0 ,-2 ,3 ,0 ,9 ,10 } ) 

[ SELECT with filter] 


,3 } [MULTISET] => MULTISET{-1 ,0 ,0 ,-2 ,3 ,0 } ) 

BLOB and SBLOB data types 

With BLOB and SBLOB data types, Informix IDS can handle large objects as 

binary data in a BYTE data type and text objects in a TEXT data type. The BYTE 

and TEXT data types, commonly known as BLOB data types or simple large 

objects, provides the capability to store images and entire documents in the 

database. BLOB data types can be stored within all the other data in the table 

space or in a separate specified BLOB space. 

BLOB data types can be used in several operational areas. Commonly, 

document retrieval systems and geographic information systems are based on 

this data type. To retrieve BLOB data with SQL, you need to define keywords, 

which are stored together with the BLOB in the data row. The benefit of storing 

large data in the database is, in addition to an easy search using keywords and a 

combination of data stored in different rows but belonging together, the 

opportunity to backup and restore or delete and update for specific data. Storing 

the data in a file in the operating system is much more of a maintenance effort. 


More advanced than the BLOB data types, smart large objects (commonly 

known as SBLOB), provide more flexibility for searching data, such as random 

I/O access to the data, which was impossible with simple large objects). 

There are two types of SBLOBs, BLOB, and CLOB. The BLOB data type is used 

to stored binary data when the CLOB data type is used only for character data. 

There types require an additional set of functions defined in the server that 

provides an API for access. They are stored in an SBLOB space (smart BLOB 

space) in the database server. 

You must create an sbspace to store the BLOB types in the server. You can 

create them with following command: 

onspaces -c -S sbspace -p -o 0 -s 4000 

We change the catalog table in the stores database to use BLOB and CLOB 

instead of BYTE and TEXT using the following command:. 

ALTER TABLE catalog MODIFY (cat_descr TEXT, cat_descr CLOB, cat_picture BYTE, 

cat_picture BLOB) 

Example 9-16 shows how to insert and retrieve from data with SBLOB data 

types, that is BLOB and CLOB. The example shows how to insert the large data 

from files into a table and how to select the same data back into files in a local file 

system. 

Example 9-16 Smart large object sample 

} 

/*--- Get the BLOB from the database back ---*/ 

$query=$dbc->query("SELECT * FROM catalog where stock_num=302 and 

manu_code='KAR' "); 


if ( $error["1"]) { 

printf(" select blobs failed with %s \n",$error["1"]); 

exit(1); 

} 

$count=1; 

$row=$query->fetch(PDO::FETCH_ASSOC); 

while ( $row ) { 

$file = fopen ("README.$count.txt","w"); 

$test=fread($row["CAT_DESCR"],100000); 

while($test) { 

fwrite ( $file, $test) ; 


} 

fclose ( $file); 

$file = fopen ("PICTURE.$count.jpg","w"); 

$test1=fread($row["CAT_PICTURE"],100000); 

while($test1) { 

fwrite ( $file, $test1) ; 


} 


$count++; 


} 

?> 

Using TEXT and BYTE (BLOB data types) is similar to SBLOB types. Users can 

try Example 9-16 on page 315 and Example 9-17 using TEXT and BYTE instead 

of CLOB and BLOB respectively. 

The BLOB data to be inserted can be read from the file without placing it in a 

variable first, which simplifies the code as shown in Example 9-17. 

Example 9-17 Insert BLOB with file 

$stmt= $dbc->prepare("INSERT INTO catalog VALUES (0,302,'KAR',?,?,'All sports 

Goods')"); 

$file = fopen ("C:\README.txt","r"); 

$file1 = fopen ("C:\picture.jpg","r"); 

$stmt->bindParam(1,$file, PDO::PARAM_LOB); 

$stmt->bindParam(2,$file1, PDO::PARAM_LOB); 


fclose($file); 

fclose($file1); 


if ( $error["1"]) { 

printf(" execute insert blobs failed with %s \n",$error["1"]); 

exit(1); 

} 

/*---try to get the BLOB from the database back ---*/ 

$query=$dbc->query("SELECT * FROM catalog where stock_num=302 and 

manu_code='KAR' "); 


if ( $error["1"]) { 

printf(" select blobs failed with %s \n",$error["1"]); 

exit(1); 

} 

$count=1; 


while ( $row ) { 

$file = fopen ("C:\README.$count.txt","w"); 


while($test) { 

fwrite ( $file, $test) ; 


} 


$file = fopen ("C:\PICTURE.$count.jpg","w"); 


while($test1) { 

fwrite ( $file, $test1) ; 


} 


$count++; 


} 

?> 


In Example 9-17 on page 316, the data was selected as a stream in string data 

type. Example 9-18 shows how to bind variables to a SELECT. The data is 

placed in the variables by column. 

Example 9-18 Select BLOB with bind 

printf(" prepare update blob columns failed with %s \n",$error["1"]); 

exit(1); 

} 

$descr="This is an PDO descr clob text"; 

$file= fopen ("C:\picture1.jpg","r"); 

$stmt->bindParam(1, $descr); 

$stmt->bindParam(2, $file); 



?> 

9.3.4 Working with PHP extensions 

In addition to the PDO drivers for the PHP PDO extension, there are two PHP 

extensions that allow you to connect to an Informix database server: 

► PHP_INFORMIX 

► IBM_DB2 

These extensions provide a set of additional PHP functions to work with an 

Informix database. In addition to the normal create, read, update, and write 

database operations, they also offer extensive access to the database metadata. 

Table 9-1 lists a few of the functions that are included in the Informix PHP 

extensions as examples. 

Table 9-1 PHP extension functions 


ifx_connect() Opens Informix Server connection 

ifx_fieldproperties() Lists of SQL field properties 

ifxus_open_slob() Opens an SLOB object 

ifx_create_blob() Creates an BLOB object 

ifx_fetch_row() Gets row as an associative array 

ifx_query() Sends Informix query 

db2_connect() Returns a connection to a database 

db2_client_info() Returns information describing DB2 database client 

db2_primary_keys() Returns a result set listing primary keys for a table 

db2_special_columns() Returns a result set listing the unique row identifier 

columns for a table 



db2_bind_param() Binds a PHP variable to an SQL statement parameter 

db2_commit() Commits a transaction 

For a complete list of all the functions that are implemented in the 

PHP_INFORMIX and IBM_DB2 extensions, refer to: 

http://www.php.net/manual/en/ref.ifx.php 

http://www.php.net/manual/en/ref.ibm-db2.php 

The PHP_INFORMIX extension 

A PHP script can connect to an Informix database using the ifx_connect() 

function that is provided in the PHP_INFORMIX extension. 

Example 9-20 shows a simple PHP script that tests connectivity with the 

PHP_INFORMIX extension. 

Example 9-20 The connect.php script 

C:\work>type connect.php 

 

C:\work>php connect.php stores_demo informix password 

Connection succeeded. 

C:\work> 

You can use functions such as ifx_query() and ifx_affected_rows() to run 

SQL statements and to retrieve the number of rows affected. Example 9-21 

demonstrates how to delete a row from the state table using the ifx_query() 

function. 

Example 9-21 The delete.php script 

C:\work>type delete.php 

Deleted 1 records 

C:\work> 

The application can select data from an Informix database using the 

ifx_prepare() and ifx_fetch_row() functions. 

Example 9-22 shows how to select the first three rows from the state table using 

a prepared statement and the ifx_fetch_row() function. 

Example 9-22 The select.php script 

C:\work>cat select.php 

 

C:\work>php select.php 

code = AK sname = Alaska 

code = HI sname = Hawaii 

code = CA sname = California 

C:\work> 

For more information and examples regarding the PHP_INFORMIX extension, 

refer to: 

http://www.php.net/manual/en/book.ifx.php 


The IBM_DB2 extension 

This PHP extension provides access to IBM Data Servers, including IBM Informix 

and IBM DB2. 

In the same way as the PDO driver, PDO_IBM, the IBM_DB2 extension requires 

the IBM CLI driver to communicate with the database server. The IBM CLI driver 

is included as part of the IBM Data Server Driver for ODBC and CLI package. 

This PHP extension provides functions such as db2_connect(), db2_exec(), and 

db2_server_info() that you can use to perform typical tasks against an Informix 


Example 9-23 demonstrates how to use the db2_connect() and 

db2_server_info() functions to retrieve metadata information from the database. 

Example 9-23 The connect_ibm.php script 

C:\work>type "C:\Documents and Settings\Administrator\db2cli.ini" 

[dsc_dsn] 


Port=9089 



C:\work>cat connect_ibm.php 

 

C:\work>php connect_ibm.php 


Database name = IDS/NT64 

Datbase version = 11.50.0000 

C:\work> 


The IBM_DB2 extension can use the connection details in the db2cli.ini 

configuration file. Refer to the 3.2.2, “IBM Data Server Driver for ODBC and CLI” 

on page 70 for more information regarding the db2cli.ini configuration file. 

You can use several functions to select data from the database. Example 9-24 

shows how to use the db2_fecth_object() function to retrieve the first three rows 

of the state table as a PHP object. 

Example 9-24 The select_ibm.php script 

C:\work>cat select_ibm.php 

 

C:\work>php select_ibm.php 


AK, Alaska 

HI, Hawaii 

CA, California 

C:\work> 

You can find a full description of the IBM_DB2 extension at: 

http://publib.boulder.ibm.com/infocenter/db2luw/v9/topic/com.ibm.db2.udb.apdv.p 

hp.doc/doc/t0023132.htm 


9.3.5 Exception handling 

Error handling or exception handling is important for all applications, including 

web-based applications. Consider an Informix PHP application that shows the 

following error message while the user is using the application: 

Warning: odbc_connect(): SQL error: [unixODBC][Informix][Informix 

ODBCDriver][Informix]User (informix) password “123456” is not able to 

connect for the database server, Server is down, SQL state 28000 in 

SQLConnect in /usr/local/apache2/htdocs/odbc/error/error.php on line 4 

In this case, fail in exception handling creates a security exposure. In the this 

section, we describe many aspects related to exception handling using Informix 

PDO. 

PHP 5 has introduced, as a part of the new object-oriented programming 

interface, the exception handling mechanism that is already used for other 

programming languages. We strongly suggest that you consider exceptions for 

the usage of Informix PDO. Additionally, you can advance this interface by 

creating, throwing, and catching your own exceptions. 

In comparison with the procedural-oriented interface, Informix PDO defines the 

following methods of expressing an error in a database environment: 

► Exceptions raised internally by the PDO based on an error condition 

► Database-generated errors, which can be captured and handled by calling the 

PDO class errorInfo() or errorCode() function 

Example 9-25 shows two exceptions raised by Informix PDO functions. One 

exception is a connection request to the database that failed because the 

specified database does not exist. The other exception is an attempt to start a 

transaction twice. 

Example 9-25 Without exception handling sample 

 

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE=HY000, 

SQLDriverConnect: -329 [Informix][Informix ODBC Driver][Informix]Database not 

found or no system permission.' in C:\Program 

Files\OpenAdmin\Apache_2.2.4\htdocs\excep1.php:2 Stack trace: #0 C:\Program 

Files\OpenAdmin\Apache_2.2.4\htdocs\excep1.php(2): PDO->__construct('informix:; 

data...', 'informix', '123456') #1 {main} thrown in C:\Program 

Files\OpenAdmin\Apache_2.2.4\htdocs\excep1.php on line 2 


Fatal error: Uncaught exception 'PDOException' with message 'There is already 

an active transaction' in C:\Program 

Files\OpenAdmin\Apache_2.2.4\htdocs\excep1.php:4 Stack trace: #0 C:\Program 

Files\OpenAdmin\Apache_2.2.4\htdocs\excep1.php(4): PDO->beginTransaction() #1 

{main} thrown in C:\Program Files\OpenAdmin\Apache_2.2.4\htdocs\excep1.php on 

line 4 

If these exceptions are not caught and processed, the application terminates. 

Example 9-26 shows the use of the basic exception handler provided by PHP 5 

to cover these errors. After an exception is caught, the action that is taken 

depends on where the error originates. For example, if the error occurs in 

connecting to the database phase and the application cannot continue, the action 

is to generate an “out of order” web page with contact details. If the error is a 

minor database error, logging the error and retrying the activity is an appropriate 

action. 

Example 9-26 Simple exception handle code 

 

Output: 

Error: There is already an active transaction. 


The error information that is generated when executing the SQL statements in 

the database server is different from the exceptions that are generated by the 

Informix PDO extension. You can use the Informix PDO errorInfo() function to 

capture the status of the last executed SQL statement in the database. This 

function returns an array with the following elements: 

► The SQLSTATE 

► The SQLCODE 

► The error message 

For the details about the meaning of the codes, refer to: 


ii-11-40709.htm#sii-11-40709 

The errorCode() function is available to retrieve the SQL statement status. This 

function returns only the SQLSTATE information. Example 9-27 shows how to 

use the errorInfo() function and its output. 

Example 9-27 ErrorInfo() sample 

 

Output: 

Array 

( 

[0] => 42S02 

[1] => -206 

[2] => [Informix][Informix ODBC Driver][Informix]The specified table 

(nonexistingtable) is not in the database. (SQLPrepare[-206] at at 

ext\pdo_informix\informix_driver.c:118) 

) 

In addition to using the generic exceptions provided by the PHP 5, you can 

extend the exception class of your own exceptions. For example, you can define 

different severities for SQL errors. Critical database errors are, for example tables 


that do not exist or the database connections, cannot be established. The 

application cannot continue with these critical errors. Non-critical errors, such as 

locking errors, can be handled by a retry. 

Example 9-28 demonstrates how to define your own exceptions with PHP 5 and 

Informix PDO. This example extends the standard exception class with two new 

database exception classes and, depending on the severity, different actions are 

taken. 

Example 9-28 Custom exceptions 


printf("NonCritError!: %s \n",$ncde->getMessage()) ; 

} catch (PDOExecption $ncde) { 

printf("Error!: %s \n",$e->getMessage()) ; 

exit; 

} 

?> 

Output: 

CritError!: [Informix][Informix ODBC Driver][Informix]The specified table (carr) is not 

in the database. (SQLPrepare[-206] at ext\pdo_informix\informix_driver.c:131) 

The following common errors can occur in setting the database connectivity: 

► Missing environment variable setting 

Setting the environment variable INFORMIXDIR is required for starting the 

Apache. If this variable is not set properly, the database connection also fails. 

Example 9-29 shows the error message when you have improper 

INFORMIXDIR set. The message occurs at the first line of any PHP program 

which is generally the connection string. If you get this message, verify that 

the INFORMIXDIR setting is correct. 

Example 9-29 Unspecified error 

Error!: SQLSTATE=HY000, SQLDriverConnect: -23101 

[Informix][Informix ODBC Driver][Informix]Unspecified System Error = 

-23101. 

► Mismatched settings 

Another important item affecting the connectivity is the setup of the Informix 

runtime environment. Informix Connect or Client SDK provides the 

connectivity at run time. If the settings between the environment variables and 

the sqlhosts do not match, you receive messages similar to the one shown in 

Example 9-30. 

Example 9-30 Wrong connection information 

/usr/local/bin/php pdoconnect.php 

Error!: SQLSTATE=HY000, SQLDriverConnect: -25555 

[Informix] [Informix ODBC Driver][Informix]Server ol_svr_custom is not 

listed as a dbserver name in sqlhosts. 


Chapter 10. User-defined routines 

In this chapter, we how to create and use user-defined routines (UDRs). A UDR 

is a routine that you create that can be invoked in an SQL statement by the 

database server or from another UDR. A routine is a collection of program 

statements that perform a particular task. By understanding UDRs, you can take 

the next step and extend the database server, either a little bit or in steps that 

lead to something bigger, such as a bladelet or DataBlade module. 


► An overview of UDRs and database extensions 

► Developing UDRs 

► DataBlades and bladelets 

10 

Extending the database server requires an understanding of the components 

that are required to implement the extension. An extension can be as simple as 

one UDR or as complex as a new data type with many supporting routines. We 

first discuss UDRs and user-defined types (UDTs) to provide the scope for what 

is needed. Then we provide examples. 


10.1 An overview of UDRs and database extensions 

IBM Informix database servers have the built-in ability to retrieve, store, 

manipulate, and sort a number of standard data types, some of which are unique 

to Informix servers. A developer can choose to modify or extend the built-in data 

types and to modify or extend how various operations work with the resulting new 

data type extensions. 

You can extend the data types using the following methods: 

► Extend operations that are used to process built-in data types. 

► Create complex data types based on built-in data types. 

► Create UDTs, both distinct and opaque data types. 

► Create new operations to process extended data types. 

Database extensions and extended data types allow the developer to make 

customized routines and functions transparent, because you have the capability 

to actually build it into the database server. The transparency is visible as: 

► Better performance through optimized routines, faster queries, and reduced 

network traffic. 

► Simpler applications in streamlined code and easy to upgrade applications. 

► Transaction control with automatic recovery, backup, and rollback capability 

that is provided by the server. 

► Scalability because database extensions scale automatically with the 

database size and user count. 

In the context of discussing UDRs and database extensions, we also mention 

DataBlade modules. A DataBlade module is a software package that extends the 

functionality of the IBM Informix database server. Each package includes SQL 

statements and supporting code written in an external language or in Stored 

Procedure Language. A DataBlade module enables the same level of support for 

new data types as the database server provides for built-in data types. 

DataBlade modules can also use SQL queries or the DataBlade API to access 

data types and routines in other DataBlade modules. 

Note: Extended Parallel Server and Standard Engine support stored 

procedures but not UDRs. 


10.1.1 Considerations for UDRs 

A UDR can be written using the IBM Informix Stored Procedure Language (SPL) 

or with an external language. A routine written with SPL is simple to use and 

easy to implement. An SPL-based UDR has flow-control extensions (conditional 

clauses and while loops) and works with SQL statements. After the routine is 

created and is ready to use, the database server parses, optimizes, and stores it 

in system catalog tables so that it is ready to execute. 

The system catalog tables are used to keep track of the information the database 

server uses to manage the database server. UDR-related information is stored in 

a small group of catalog tables that provide information about the UDR layouts. 

UDRs include the following common catalog tables: 

► sysprocedures table 

Used to track the name and owner and to indicate whether the UDR is a 

user-defined function or a user-defined procedure (functions return values but 

procedures do not). 

► sysprocauth table 

Tracks who can execute the procedure. 

► sysprocbody table 

Contains the actual code for the SPL routines. 

UDRs can also be written with an external language. The body of an 

external-language routine allows language-based operations such as flow control 

and looping, while also using special Informix library calls to access the database 

server. 

The database server stores information for external-language routines in the 

following system catalog tables: 

► sysprocedures table 

The information kept in this table is same as the SPL UDR. 

► sysroutinelangs table 

This table tracks the language information. 

► syslangauth table 

This table tracks the users of the server who can use the particular external 

language. 

You need to use an appropriate compiler to parse and compile an 

external-language routine into an executable format. We discuss this with 

Chapter 10. User-defined routines 331

10.1.2 About UDRs 

specific examples of the language and API methods that are available for writing 

these extensions. 

The external languages that can be used are: 

► C 

To execute SQL statements in C UDRs, you must use the DataBlade API, and 

you cannot use ESQL/C. To write routines in C, you need a C compiler. YOu 

can find additional information about writing UDRs in C in the IBM Informix 

DataBlade API Programmer’s Guide, Version 11.50, SC23-9429, and IBM 

Informix DataBlade API Function Reference, Version 11.50, SC23-9428. 

► Java 

To write Java routines, you must use IBM Informix database server with 

J/Foundation and with the Java Development Kit (JDK) to compile your Java 

routines. You can find additional information about how to write Java UDRs in 

J/Foundation Developer's Guide, Version 10.0, G251-2291. 

Table 10-1 lists the UDR types that are supported by SPL, C, and Java in IBM 

Informix database server. 

Table 10-1 Supported UDR tasks by languages 

UDR task SPL routines C routines Java routines 

Cast function Yes Yes Yes 

Cost function No Yes No 

End-user routine Yes Yes Yes 

Iterator function No Yes Yes 

Negator function Yes Yes Yes 

Opaque data type support No Yes Yes 

Parallelizable UDR No Yes Yes 

Statistics function No Yes Yes 

Selectivity function No Yes No 

User-defined aggregate Yes Yes Some 

Operator function Yes Yes Yes 

Operator-Class function Yes Yes Yes 


The following terms are used in this table: 

► Cast: A routine to convert from one data type to another. Built-in data types 

have automatic casts between most data types. For UDTs, casting must be 

defined from scratch. 

► Cost function: A routine that informs the optimizer of cost factors for execution 

of a particular UDR. 

► End-user function: A routine that is used to encapsulate multiple SQL 

statements into one function. 

► Iterator function: A routine that is designed to return to its calling SQL 

statement several times, returning a value each time. 

► Negator function: A routine used for a NOT condition that involves a Boolean 

UDR. 

► Opaque data type support: When you create a new data type, you must 

provide several basic support functions for your UDT. The following functions 

are required: 

– Text input and output routines 

– Binary send and receive routines 

– Text import and export routines 

– Binary import and export routines 

► Parallel UDR: A routine that can run in parallel within parallel queries. 

► Statistics function: A routine to create distribution statistics for a UDT. 

► Selectivity function: A routine to determine the percentage of rows for which a 

Boolean UDR is expected to return true. 

► User-defined aggregate: A SQL invoked routine that takes values selected 

and returns information about those rows (a summarizing method). 

► Operator function: A routine that is used within expressions with a symbol, 

such as “+,-,,=”. Built-in data type operators cannot be extended. All UDTs 

require some operators to function within an SQL context. 

► Operator-Class function: A set of operators that the server associates with 

how to build an access method (that is, an index), how to arrange values in 

the access method, how to select values based on operator function, and 

ways to allow the query optimizer to consider using the access method to 

return results for a query. 

For more details about any of these functions and for details about functionality 

that we do not discuss here, see IBM Informix User-Defined Routines and Data 

Types Developer's Guide, Version 11.50, SC23-9438. 


Invoking a UDR 

You can invoke a UDR implicitly or explicitly. Implicit invocation is the result of an 

operator function, an implicit cast, or some type of query processing. For this 

book, we mainly discuss explicit invocation. You can use either EXECUTE 

PROCEDURE or EXECUTE FUNCTION statements to run a UDR. 

When the database server executes an SQL statement that contains a UDR, it 

loads the UDR executable code as a shared-object into memory. It determines 

which shared-object file to load from the externalname column of the row in the 

sysprocedures system catalog table that describes the UDR. The sysprocedures 

entry is created when you register the UDR, as a result of the CREATE 

FUNCTION or CREATE PROCEDURE statement. 

In more general terms, when you invoke a UDR, the database server parses the 

statement into syntactic parts, call the system catalog to resolve the routine 

parts, generate a query plan, and then execute the query. If the query involves 

more than one database, each database requires that all the UDRs and UDTs 

must be registered in the participating databases. 

10.1.3 Considerations for extending data types 

A significant aspect of UDR is the support for an extended data type. IBM 

Informix database servers have several built-in data types. Why do we need 

more? 

An extended data type is a new data type that has different core properties, new 

functionality, and new operator methods that go beyond a basic data type. 

As an example, consider a datetime data type. Imagine, as a programmer if you 

had to add “a day and a half” to a specific datetime event. Intuitively, we 

recognize that the value “‘day and a half” is an interval of time, but the database 

serve does not recognize this construct as an interval. We need to convert it 

manually to a usable interval, and then add it to a datetime value. 

With a UDR, an unconventional interval name such as this can be passed 

through a function, which translates it to an “normal” interval automatically, 

applies the addition operation, and returns a datetime value with the result. To do 

this, we apply a functional behavior change, which extends the data type. The 

result of processes such as this can simplify a repeating data task and make the 

development task easier. 


A quick review of the data type hierarchy is useful. Figure 10-1 shows a summary 

of these data types. 

Figure 10-1 Hierarchy of data types in Informix servers 

The extended data types can be either UDR types or complex data types. We are 

especially interested in UDTs, which can be described as follows: 

► Distinct: Internally, this data type is stored the same as a source data type, 

but it is overlaid with different casts and functions defined beyond the basic 

source type. The server sees distinct types as different from the source type. 

It is necessary to tell the server: 

– Source data type information and how the internal structure is defined. 

– The functions of how this data type interacts with its internal structure. 

– The operations that are valid with this distinct data type. 

– Any secondary access methods on how to handle this type. 

– Cast functions to move data in and out of the distinct type are automatic. 

► Opaque: A fundamental, user-defined data type. It cannot be broken into 

smaller pieces, although it can serve as the building block for other data 

types. The internal structure of the opaque data type is invisible to the server. 

When you define and use an opaque type, the developer must provide all of 

the following: 

– How the internal structure is defined. 

– The functions that enable routines to interact with its internal structure. 

– The operations that are valid with this distinct data type. 

– Any secondary access methods on how to handle this type. 

– Cast functions to move data in and out of the distinct type need to be 

provided. 


10.2 Developing UDRs 

To develop a UDR, plan it first and then write the routine. We follow the 

recommendations given in the UDR and Data Types Developers Guide for 

planning our routines: 

► Use a sensible name. 

► Avoid modal arguments (an argument in the function determines how the 

function will work). 

► Always declare routine parameter data types. 

► Declare the type that is returned when the routine is returning a value 

The source for an external routine resides in a separate text file. To prepare UDR 

source code: 

► You will compile the C-language UDR and store the executable version in a 

shared-object (.so or .o on UNIX) file. 

► Compile the Java-language UDR and store the executable version in a .jar 

file. 

You must install shared object files and .jar files on all database servers that 

need to run the UDRs, including database servers involved in Enterprise 

Replication (ER) and High-Availability Data Replication (HDR). The shared object 

files and .jar files need to be installed under the same absolute path name. 

Tip: Although not required, use the DataBlade Developer’s Kit (DBDK) to help 

write UDRs is advantageous. DBDK books and software can help enforce 

standards that facilitate migration between different versions of the database 

server. Because external-language routines are external to the database, be 

aware that you must compile the UDR source code and store it where the 

database server can access it when the routine is invoked. 

For information about C UDRs, refer to IBM Informix DataBlade API 

Programmer’s Guide, Version 11.50, SC23-9429 and IBM Informix DataBlade 

API Function Reference, Version 11.50, SC23-9428. For information about Java 

UDRs, refer to the J/Foundation Developer's Guide, Version 10.0, G251-2291. 

10.2.1 UDR examples in SQL 

You can use Informix Stored Procedure Language (SPL) statements to write 

routines and then store these SPL routines in the database. SPL extends SQL 

and helps to reduce SQL coding by minimizing the visible code in large SQL 


operations. It has the advantage that it is run as a server-side routine, the 

executable code stays inside the engine, and it is optimized only as needed. The 

end result is lower application startup costs and better performance. As an SQL 

extension, SPL can do flow control, such as looping and branching. SPL routines 

can also execute routines written in C or other external languages, and other 

UDR routines can execute SPL routines. 

In this section, we provide examples of UDRs written in SQL. As we do so, 

consider the following rules for SQL UDRs: 

► If you use any parameters, they must be declared as built-in or user-defined 

data types. 

► An SPL routine does not have access to the user state of its execution 

sequence. If the routine is going to be called more than once and if you want 

to retain information about previous executions in the transaction, use an SPL 

routine that states WITH RESUME as a part of the RETURN statement for 

multiple executions of the same SPL routine within the same routine 

sequence. 

► When an SPL routine is executed, the parameters (also known as the 

dependency list) is checked. If it is determined that an item in the dependency 

list needs reoptimization, optimization occurs at this point. If an item needed 

in the execution of the SQL statement is missing (for example, a column or 

table is dropped), an error is returned. 

► UDRs can be overloaded, meaning that a function can have more than one 

way to operate, depending on the list of data types that are provided as 

parameters. There is a precedence hierarchy to decide how the parameter list 

is executed. A precedence hierarchy to decide the execution sequence of the 

parameters can be important if you have more than one UDR with the same 

name but a different parameter list. For more information, see IBM Informix 

User-Defined Routines and Data Types Developer's Guide, Version 11.50, 

SC23-9438. 

Using a stored procedure method for a UDR is simple, as long as you can 

recognize the incoming and outgoing parameters properly. The incoming 

parameters, which are provided in the function definition, must have data types 

defined when the parameter is first created and declared. The parameter values, 

which are to be returned from the function, also should have declared data types. 

By following this general rule, you can avoid many of the initial problems you can 

get with SPL UDRs. 

For the routines with SPL, we use the Informix stores sample database, defined 

as stores@demo_on. 


One variable in, one result out 

For this example, we want a function that provides a count of all the orders that 

are received in a numerical month (N) from the orders table of the stores 

database. This example demonstrates what happens when selecting an 

aggregating value, once. 

Example 10-1 shows the function code and ways to invoke the function to get 

output. 

Example 10-1 CREATE FUNCTION new_orders (month_num INT) 

CREATE FUNCTION new_orders ( month_num INT ) 

RETURNING INT ; 

DEFINE nrows INT; 

SELECT COUNT(order_date) INTO nrows FROM orders 

WHERE month(order_date)=month_num; 

RETURN nrows; 

END FUNCTION; 

# -- Execute it as a function: 

EXECUTE FUNCTION new_orders(5); 

(expression) 

7 

# -- Execute it as a select statement. 

# -- Note that we have to force “first 1” as a criteria so we can assure we are 

# -- only getting one value. Otherwise we would get an error. 

SELECT FIRST 1 new_orders(5) FROM orders; 

(expression) 

7 

One variable in, several results out 

Example 10-2 performs three SELECT statements, and each statement does an 

aggregation, returning one value from each select. It returns three values and 

labels each value in the returned result. This example shows how to aggregate 

three separately selected value returns in one call and still not use a cursor. 

Example 10-2 Selecting three and returning three 


RETURNING INT as TotalOrders,INT as ShippedOrders,INT as Backorders; 

DEFINE nrows INT; 

DEFINE mrows INT; 

DEFINE b_rows INT; 


SELECT COUNT(ship_date) INTO mrows FROM orders 

WHERE month(ship_date)=month_num; 

SELECT COUNT(order_date) INTO nrows FROM orders 

WHERE MONTH(order_date)=month_num; 

SELECT COUNT(order_date) INTO b_rows FROM orders 

WHERE MONTH(order_date)=month_num AND ship_date IS NULL; 

RETURN nrows,mrows,b_rows; 

END FUNCTION; 

# -- Since we are returning three values with labels, calling the execute 

# -- function is the most appropriate way to make our SQL call. 


totalorders shippedorders backorders 

7 3 1 

Using the WITH RESUME clause to return a cursor result 

Example 10-3 collects better details for the new orders. To return a detailed 

listing of orders made, it uses the WITH RESUME clause in the function. In this 

case, we assume (and expect) more than one row is returned. So, the WITH 

RESUME clause is needed. 

Example 10-3 A WITH RESUME ROUTINE that uses a cursor 


RETURNING INT as Num, INT as ord_num; 

DEFINE ord_num INT; 

DEFINE Num INT; 

LET Num=1; 

FOREACH cursor1 FOR 

SELECT order_num INTO ord_num FROM orders 

WHERE month(order_date)=month_num 

RETURN Num, ord_num WITH RESUME; 

LET Num=Num+1; 

END FOREACH; 

END FUNCTION; 


------num ord_num----- 

1 1001 

2 1002 

3 1003 

4 1004 


10.2.2 UDRs in Java 

5 1005 

6 1006 

7 1007 

Multi-table select using a cursor 

Example 10-4 performs a multi-table join with a summary expression return and 

a group by. We ask for all the orders placed in a specific month, the name of the 

person placing the order, and the total amount for each order. 

Example 10-4 A multi-table select using a cursor 


RETURNING INT as Ord_Num, char(15) as ord_fname, 

char(15) as ord_lname, money(8,2) as Amt; 

DEFINE ord_num INT; 

DEFINE ord_fname char(15); 

DEFINE ord_lname char(15); 

DEFINE Amt money(8,2); 

FOREACH cursor1 FOR 

SELECT o.order_num, c.fname,c.lname,sum(i.quantity*i.total_price) 

INTO ord_num, ord_fname, ord_lname, Amt 

FROM orders o, customer c, items i 

WHERE month(order_date)=month_num 

AND o.customer_num=c.customer_num 

AND i.order_num=o.order_num 

group by o.order_num,c.fname,c.lname 

RETURN ord_num, ord_fname, ord_lname, Amt WITH RESUME; 

END FOREACH; 

END FUNCTION; 

You must distinguish between JDBC and Java Virtual Machine (JVM) 

applications. You can use JDBC to write stand-alone applications. If you want to 

connect with to databases that support Java, you typically write stand-alone 

JDBC applications, because these applications require specific driver methods to 

communicate with other database servers. When you write a Java UDR, you 

must use the IBM Informix JDBC Driver, which is based on the JDBC 2.0 API. 

The generated code is processed by a JVM that runs as a process inside IBM 

Informix Server. The generated code (.jar file) is stored in an sbspace and can 

also refer to a .jar file in a storage location outside of the server. 

Java allows you to create UDRs, cast support functions, aggregates, and opaque 

data type support routines. However, Java routines cannot handle row or 

collection data types. 


For ordinary UDR with IBM Informix database servers, you can use the Java 

Developers Kit (version 1.5 at this writing). A JVM comes pre-installed with the 

IBM Informix database server (with J/Foundation). To confirm it is present, make 

sure that you have an existing directory path to the 

INFORMIXDIR/extend/kraratoa directory. 

Java-based UDR, when developed, is placed into a Java archive (.jar) file. The 

.jar file is stored inside an sbspace, or it can have additional supporting files on 

the file system. If the .jar file is large or perhaps proprietary, you can leave it on 

the file system. Store smaller .jar files or files that you might want to update 

frequently in the sbspace. 

Configuration 

Make sure that you use the JVM system that came with your server engine, and 

make sure the onconfig file and environment variables are set to accurate 

working paths. The environment settings for our testing setup had the following 

variables in the environment: 

JRE_HOME=/usr/lib/jvm/java/jre 

JAVA_BINDIR=/usr/lib/jvm/java/bin 

JAVA_HOME=/usr/lib/jvm/java 

SDK_HOME=/usr/lib/jvm/java 

JJDK_HOME=/usr/lib/jvm/java 

JAVA_ROOT=/usr/lib/jvm/java 

The JAVA_ROOT environment variable is mostly determined by the developer. It is 

the path to the file system directory where you are developing your .jar files: 

CLASSPATH=location_for_your_java_classes:.:.:. 

The INFORMIXDIR/etc/ONCONFIG file also has a small group of parameters that 

must have verified settings. The following parameters are standard: 

JVPJAVAHOME $INFORMIXDIR/extend/krakatoa/jre 

JVPHOME $INFORMIXDIR/extend/krakatoa 

JVPPROPFILE $INFORMIXDIR/extend/krakatoa/.jvpprops 

JVPJAVALIB /bin 

JVPJAVAVM jvm 

The JVPJAVALIB and JVPJAVAVM parameters in the onconfig file are important for 

development. The following parameter specifies the name of the log file to which 

Java problems are written (make sure the path exists): 

JVPLOGFILE $INFORMIXDIR/jvp.log 

If you are going to use external .jar files, you must add them to JVPCLASSPATH: 

JVPCLASSPATH $INFORMIXDIR/extend/krakatoa/krakatoa.jar:$INFORMIXDIR/extend/krakatoa/jdbc.jar 


Note: The paths for .jar files that are added to JVPCLASSPATH are visible 

only after you add them to the onconfig file and restart the database engine. 

Routine examples in Java 

In the examples that follow, we create our Java routines in /work/, which defines 

the UNIX directory that we use for our working CLASSPATH. You must change 

the directory path in some of the code expressions if you use a different directory. 

After you compile the code, the source code is not used for execution, but keep it 

in a safe place in case you want to improve it later. 

A function extension 

This example illustrates a simple way to extend functionality. This routine 

provides an SQL function to “multiply a value times 10.” The developing 

procedure is as follows: 

1. Create a simple class file named Times.java in the working JVPCLASSPATH 

directory. Example 10-5 shows the source code. 

Example 10-5 A Java function to multiply a value times 10 

/*Times.java */ 

public class Times { 

public static int TimesTen(int x) { 

return x * 10; 

} 

} 

2. At a command prompt, compile the file using the following command: 

javac Times.java 

3. Compress it into a .jar file: 

jar cvf Times.jar Times.class 

As this runs, it shows output similar to the following: 

added manifest 

adding: Times.class(in = 245) (out= 187)(deflated 23%) 

4. Register the routine: 

Start dbaccess to connect to the database and run the following SQL to 

register and add the .jar file into our sbspace: 

execute procedure sqlj.install_jar ("file://work/Times.jar" , "Times_jar"); 

Routine executed. 


5. With the .jar file in storage and accessible, from dbaccess, we create a 

function that calls our routine in the .jar file. See Example 10-6. 

Example 10-6 Calling routine 

create function times_ten(value int) returning int 

with (class = "jvp") 

external name "Times_jar:Times.TimesTen" 

language JAVA; 

6. The procedure is ready to run. Test it in dbaccess: 

EXECUTE function times_ten(13) 

(expression) 

130 

For an alternate method, try: 

SELECT ship_charge, times_ten(ship_charge) X10 FROM orders; 

A Java UDR with two input parameters 

This example demonstrates how to create a Java routine with multiple input 

parameters. Java language and IBM Informix servers express decimals in 

different ways. This example creates a new sales tax function, Salestax, that 

includes a new Java function and the existing Times_ten function created in “A 

function extension” on page 342. 

We need to include an external standard Java library that has a math class. You 

might find that multiplying decimal values in Java is different than what you might 

be used to. In addition, Java uses a different naming convention than Informix 

data types. If you get the class wrong or the library is incorrect, things simply do 

not work, and you will get errors. 


We use the following procedure to create the salestax function: 

1. Create a Java class called Tax.java, using an editor such as vi. 

Example 10-7 shows the source code. 

Example 10-7 The Tax.java class 

/*Tax.java*/ 

import java.math.BigDecimal; 

public class Tax { 

public static BigDecimal salestax(BigDecimal x,BigDecimal xtax ) 

{ 

BigDecimal ratePlusOne = xtax.add(BigDecimal.valueOf(1)); 

BigDecimal afterTax = x.multiply(ratePlusOne); 

afterTax = afterTax.setScale(2, BigDecimal.ROUND_HALF_UP); 

return (afterTax); 

} 

} 

2. Compile the file. At a command prompt, run the following command: 

javac Tax.java 

3. Compress the file, and add it to the existing .jar file (named Times.jar). 

jar cvf Times.jar Tax.class 

As this runs, it shows a line similar to the following: 

added manifest 

adding: Tax.class(in = 546) (out= 318)(deflated 41%) 

4. Add the updated .jar file to sbspace. 

For this example, we want to update an existing function that already exists in 

the sbspace .jar file. Because we cannot replace an existing function in a 

sbspace .jar file directly, update an sbspace .jar function, we must replace 

the entire .jar file. To do this, we must remove (drop) the sbspace .jar file, 

then replace it with an updated version from our working path. 

A .jar file in an sbspace must be empty to drop the .jar file. Drop all the 

UDRs in the .jar file to empty it. Otherwise, you receive the following error 

message: 

“Invalid jar removal. All dependent UDRs not dropped”. 

Our Times_jar file exists in the database. To drop the function, we start 

dbaccess, connect to the database, then run the following command: 

DROP FUNCTION times_ten; 

Now, we can remove the .jar file: 

EXECUTE PROCEDURE sqlj.remove_jar ("Times_jar"); 


5. Add the updated .jar file into sbspace. Run the following SQL: 

EXECUTE PROCEDURE sqlj.install_jar ("file://work/Times.jar" , "Times_jar"); 

6. The updated .jar file is now in sbspace storage. Re-create the dropped 

Times_ten function: 

create function times_ten(value int) returning int 


external name "Times_jar:Times.TimesTen" 


7. Add the new function to call on the same .jar file: 

create function salestax(value decimal,xtax decimal) 

returning decimal(8,2) 


external name "Times_jar:Tax.salestax" 


8. Now, can test the expanded function from dbaccess: 

EXECUTE FUNCTION salestax(250.00,.065); 

(expression) 

266.25 

As an alternative test using SQL, try: 

SELECT o.order_num, 

salestax (sum(i.quantity*i.total_price), .065) Amt_w_Tax 

FROM orders o, items i WHERE month(order_date)=5 

AND i.order_num=o.order_num group by o.order_num 

Creating a routine that uses external Java APIs 

This example demonstrates how to create a Java UDR that requires support from 

one or more Java APIs that lie outside the database server. The import 

references in the code indicate that an external Java API exists to help support 

the UDR. The references on the import list remain outside the database server. 

The JVM runs using the .jar file calls in the sbspace storage location and sends 

calls to the external Java functions based on the import reference in the .jar file. 

Note that the import reference does not have a full directory path. Any Java API 

or .jar file that is not residing in an sbspace is external to the instance. To help 

the server instance find external .jar files, you must supply all JAR API path 

locations in the onconfig file. 

Note: The onconfig file must be updated so the JVM knows the directory path 

for any supporting APIs. The full path location for the supporting Java file 

specified on an import list must be included in JVPCLASSPATH. 


For our example, JVPCLASSPATH is set to: 

/usr3/11.50/extend/krakatoa/krakatoa_g.jar:/usr3/11.50/extend/krakatoa/jdbc_g.j 

ar:/usr3/11.50/extend/krakatoa/jre/lib/rt.jar:/work/mailapi.jar:/work/activatio 

n.jar:/work/smtp.jar 

For our example to work, the engine needs the Java mail API classes. The files 

that are required are mailapi.jar, activation.jar, and smtp.jar, which are 

available at: 

http://java.sun.com/products/javamail/downloads/index.html 

To create the sendmail routine: 

1. Install the downloaded .jar files, and add .jar files with full path to 

JVPCLASSPATH. 

In this example, the paths are /work/mailapi.jar, /work/activation.jar, 

and /work/smtp.jar. 

2. Create the file MailClient.java as shown in Example 10-8. You have to 

update the italicized references in the example with your own information. 

Example 10-8 An SQL based sendmail() UDR 

---- MailClient.java --import 

javax.mail.*; 

import javax.mail.internet.*; 


import java.util.Properties; 

public class MailClient 

{ 

public static void send(String to, String text) 

{ 

try 

{ 

MailClient client = new MailClient(); 


Properties props = System.getProperties(); 

props.put("mail.smtp.host", "smtp.server.com"); 

Session session = Session.getDefaultInstance(props, null); 

Message message = new MimeMessage(session); 

message.setFrom(new InternetAddress("Name_showing@fromfield")); 

message.addRecipient(Message.RecipientType.TO, new InternetAddress(to)); 

message.setSubject("Message from the database"); 

message.setText(text); 

Transport.send(message); 

} 

catch(Exception e) 

{ 

e.printStackTrace(System.out);

} 

} 

} 

---- MailClient.java --- 

3. Compile and compress your file: 

javac MailClient.java 

jar cvf MailClient.jar MailClient.class 

4. Install the .jar file into the sbspace: 

EXECUTE PROCEDURE sqlj.install_jar ("file://work/MailClient.jar" , 

"MailClient_jar"); 

Make sure JVPCLASSPATH is set as indicated in step 1. 

5. Create the sendmail procedure from dbaccess: 

CREATE PROCEDURE sendemail(to LVARCHAR, message LVARCHAR) 

WITH (class = "jvp") 

EXTERNAL NAME "MailClient_jar:MailClient.send" 

LANGUAGE JAVA; 

6. Test the procedure: 

EXECUTE PROCEDURE sendemail('dba@mybiz.com','Error deleting from table'); 

Troubleshooting tips 

Sometimes you might have trouble getting a Java UDR to run. The following 

points of exposure for errors are possible: 

► At the time of a Java compile 

If you get an error here, the issue relates to a Java language problem, most 

likely resulting from syntax or a Java method. Consult a Java Programming 

Language Guide for assistance. 

► At the .jar installation point or later 

Check the jvp.log at the path in the onconfig file specified by the JVPLOG 

parameter. You should see no errors at the time of install, and no errors at run 

time. When you start the server instance the JVM starts, .jar files load into 

the process memory as needed. The MSGPATH file (online.log) often 

reveals the success or failure of JVM and .jar file loading. If the files cannot 

load, they cannot run. 

► UDR runtime errors 

If there are errors, study the Java error messages returned, and determine 

the cause for whatever did not resolve. 

Troubleshooting can be a trial and error approach. When you have an 

understanding of how the provided UDR examples work, do them over again, 


10.2.3 UDRs in C 

and break something in the Java code. Go through the example with slightly 

broken syntax and review the results. For example, in the BigDecimal code 

example, change BigDecimal to Float or Double, and work through the example 

again. 

The C programming language allows you to create UDRs, cast support functions, 

aggregates, and opaque data type support routines. C can also handle row and 

collection data types. Working with C UDR adds an extra layer of difficulty 

because these routines have to be compiled using a compiler, specific to the 

system and operating system where you have products installed. Compiled C is 

not stored in sbspace, but rather it is stored outside the server. 

In addition to compiler difficulties, it is a good idea to develop and test UDRs on a 

development server and not in a production environment. C UDR code runs as a 

database server process that works closely with internal structures. The routine 

should not do anything that would negatively affect the database server. A poorly 

designed C UDR is likely to crash the server. If you plan to work with C UDRs, 

the following resources are good reference books: 

► IBM Informix User-Defined Routines and Data Types Developer's Guide, 

Version 11.50, SC23-9438 

► IBM Informix DataBlade API Programmer’s Guide, Version 11.50, SC23-9429 

► IBM Informix DataBlade API Function Reference, Version 11.50, SC23-9428 

If you are interested in using C++ Datablade modules, the IBM Informix 

Developer Zone that provides the latest recommendations on C++ programming 

options at: 

http://www.ibm.com/software/data/developer/informix 

Routine examples in C 

In this section, we undertake a few examples written in C. With Java, we have 

portability that extends across platforms, but some of our functionality is limited. 

C is flexible because it can extend the database by way of data types, new 

functions, and new operators. For each database across an enterprise, the 

extensibility that you provide through C must be specifically compiled with each 

operating system. For the examples in this section, we use a Solaris system. 

A simple function using C 

For our first example, we start with a function similar to what we did in our Java 

example, a multiplying function. For each of our C examples, we must include the 

DataBlade API files (referenced in the example as mi.h and milib.h). The 


DataBlade APIs provide the interface to allow C language calls to interface with 

IBM Informix database SQL calls. To prevent a conflict with our times_ten Java 

UDR function, we name this example times_five. 

To create this routine: 

1. Create the text file that holds the C code. Example 10-9 shows the source file 

times.c. 

Example 10-9 A C UDR that multiplies times five 

#include 

#include "mi.h" 

#include "milib.h" 

mi_integer* TimesFive(mi_integer value); 

mi_integer* TimesFive(mi_integer value) 

{ 

return (mi_integer *) (value * 5); 

} 

2. Compile and link the C code. 

The compile command (cc or gcc) depends on the operating system. The first 

way to identify your compiler is to examine the text of man cc (on UNIX), or 

check the command for your operating system compiler in the 

INFORMIXDIR/release/en_us/0333/ids_machine_notes_vers.txt file. 

At a minimum, your compile line for UDR preparation usually includes: 

-DMI_SERVBUILD -KPIC -I$INFORMIXDIR/incl/public -I/$INFORMIXDIR/incl 

Where 

– -DMI_SERVBUILD is the flag to indicate that this is a server-oriented C UDR 

application which uses the DataBlade API (required). 

– -KPIC is the flag to indicate that the symbol table is dynamic (for UNIX and 

Linux only). 

– -I$INFORMIXDIR/incl/public and -I/$INFORMIXDIR/incl are the location 

of the mi_ libs. 

The compile command for our code sample (on Solaris) is: 

cc -DMI_SERVBUILD -KPIC -I$INFORMIXDIR/incl/public -I/$INFORMIXDIR/incl -o 

times.o -c times.c 

Run the link command to put the compiled object file into our Blade library file: 

ld -dy -G -Bsymbolic -o times.bld times.o 


3. Set the bld file permissions as user informix: 

chmod 555 ./times.bld 

4. In dbaccess, after connecting to the database, create the times_five 

function: 

CREATE FUNCTION times_five(value int) RETURNING int 

WITH (handlesnulls) 

EXTERNAL NAME "/work/times.bld(TimesFive)" 

LANGUAGE C; 

Adjust the external work path as needed. 

5. Test the routine: 

execute function times_five(20); 

(expression) 

100 

In Java UDR, the .jar file serves as a library (collection-repository) for all of the 

compiled routines. In C, a collection of compiled routines is stored in a shared 

library (.so or .o) file. On Windows, a shared object file has a .dll extension 

(dynamic link library). 

Creating a C routine using large object column 

The next example explores the use of working with a large object column 

reference. Without a text search DataBlade, searching a character large object 

(CLOB) file for a particular value can be a laborious SQL task. This example 

shows how to access a CLOB file, copy the CLOB contents into an LVARCHAR, 

and search for a specific text item, while using a simple function. We create a C 

file that handles two parameters. The first parameter is a CLOB column 

reference, the second parameter is the LVARCHAR text value for our search. It 

returns a count for the number of successful finds. 

To implement this search routine: 

1. Create the CLOB column search routine source file un.c as shown in 

Example 10-10. 

Example 10-10 A UDR for searching a CLOB 

#include 

#include 

#include 

#include 

#include 

#include 

typedef unsigned char byte; 

mi_integer contains(MI_LO_HANDLE* loptr, mi_lvarchar* pattern, MI_FPARAM* fp); 


mi_integer contains(MI_LO_HANDLE* loptr, mi_lvarchar* value, MI_FPARAM* fp) 

{ 

mi_unsigned_integer crc = (mi_fp_argisnull(fp, 1) == MI_TRUE) ? 0 : 

(mi_unsigned_integer)1; 

MI_CONNECTION *conn; 

MI_LO_SPEC *lo_spec = NULL; 

MI_LO_FD lo_fd; 

MI_LO_STAT *lo_stat = NULL; 

char *buff = NULL; 

char *pattern = NULL; 

mi_integer buffsize = 4096; 

mi_integer found=0; 

mi_integer result=0; 

pattern = mi_lvarchar_to_string(value); 

if ((conn = mi_open(NULL, NULL, NULL)) == NULL) return (mi_integer) -1; 

if ((buff = (char*)mi_alloc(buffsize)) == NULL) return (mi_integer) -2; 

if ((lo_fd = mi_lo_open(conn, loptr, MI_LO_RDONLY)) == MI_ERROR) 

return (mi_integer) -3; 

do { 

if ((result = mi_lo_read(conn, lo_fd, buff, buffsize)) == MI_ERROR) 

break; 

if (result == 0) 

break; 

if (strstr(buff,pattern)!=NULL) 

{ 

found=1; 

break; 

} 

if (result < buffsize) 

break; 

} while(1); 

mi_lo_close(conn,lo_fd); 

if (buff) 

mi_free(buff); 

return (mi_integer)found; 

} 

2. Compile and link the C routine. We use the following Solaris compile line: 

cc -DMI_SERVBUILD -KPIC -I$INFORMIXDIR/incl/public 

-I$INFORMIXDIR/incl/public -I$INFORMIXDIR/incl/esql -I/$INFORMIXDIR/incl -o 

un.o -c un.c 

Here is the link line: 

ld -dy -G -Bsymbolic -o un.bld un.o 

3. Set the bld file permissions as user informix: 

chmod 555 ./un.bld 


4. Create the function in dbaccess. 

create function contains(clob,lvarchar) 

returns integer 

external name '/work/un.bld(contains)' 

language C; 

5. Set up for testing. Create a table and populate it with our c file. 

CREATE TABLE tclob (c1 INT, c2 CLOB); 

INSERT INTO tclob VALUES (1,filetoclob('un.c','server')); 

6. Test the routine: 

SELECT c2 FROM tclob; 

SELECT CONTAINS(c2,'pattern') FROM tclob; 

SELECT CONTAINS(c2,'nopattern') FROM tclob; 

SELECT c1 FROM tclob WHERE CONTAINS(c2,'buff')=1; 

Troubleshooting tips 

To track down the cause of problems with C UDRs, the most affective approach 

is to use a debugger. To debug your UDR, use a debugger that can attach to the 

active server process and access the symbol tables of the dynamically loaded 

shared object files. On UNIX and Linux, the debugger and dbx utilities meet these 

criteria. To start a debugger, enter the following command at the shell prompt, in 

which pid is the process identifier of the CPU or virtual processor: 

debugger -pid 

This command starts the debugger on the server virtual-processor process 

without starting a new instance of the virtual processor. For more information 

about available debugger commands, see the debugger manual page, and learn 

more in the information center: 


dapip.doc/sii111026637.htm 

10.3 DataBlades and bladelets 

Your initial collection of UDRs increases over time. It might not be long until you 

have UDRs, special functions, and stored procedure UDRs that reduce work 

complexity and provide great functionality. If you choose not to write your own 

DataBlade, you can still choose from a nice selection of DataBlade modules. Any 

DataBlade module you use provides functions that might increase the usefulness 

of business data dramatically or that might perhaps generate income for you—as 

a software developer that develops and sells licensed DataBlades. 



IBM Informix has several books on the subject of planning, designing, and 

implementing DataBlades. With a taste of the programming examples presented 

earlier in this chapter, you might be ready to take the next step and program a 

DataBlade in C or Java. From a technical perspective, IBM Informix DataBlade 

Developers Kit User's Guide, Version 4.20, G229-6366 is specifically oriented to 

the development of DataBlade modules. It provides detailed help for 

programming DataBlade modules in Java and C. 

If you want to work with a DataBlade before you decide whether you have a need 

to write your own, the sections that follow provide an overview of the DataBlades 

that are available with IBM Informix Server. 

Configuration for a Datablade module requires the following steps: 

1. Prepare the database serve. 

2. Install the DataBlade. 

3. Register the DataBlade. 

Conceptually, the process is the same, regardless of the operating system and 

hardware. Small differences exist in interface or command lines, which we will 

point out. 

Prepare the database 

Database preparation involves setting up environment variables and making sure 

the database you are going to use with a DataBlade is set to a logged database 

in advance. 

The environment settings required are as follows: 

► On UNIX and Linux: LD_LIBRARY_PATH, INFORMIXSERVER, and 

ONCONFIG 

► On Windows: INFORMIXSERVER and ONCONFIG 

When you get to the step for BladeManager usage, you also require an 

environment setting for LD_LIBRARY_PATH. 

Although a logged database is not required for every DataBlades, a logged 

database can help avoid concurrency problems and thus is recommended. Also, 

while it is the case that not all DataBlade modules require a logged database, 

some of them do require logged sbspace. Keep this in mind as you install and 

configure the DataBlade that you select. 


Installing the DataBlade 

Any DataBlades that are installed with IBM Informix Servers are installed in 

separate subdirectories under the INFORMIXDIR/extend directory. Several 

subdirectories for DataBlades are established when the IBM Informix Server is 

installed. There might be some variation to the list, based on your exact version 

and operating system. 

Example 10-11 shows the subdirectory listing for 11.50.UC6 on Linux with 

J/Foundation. 

Example 10-11 A sample INFORMIXDIR/extend subdirectory 

opt/IBM/informix/extend:> ls 

binaryudt.1.0 ifxmngr LLD.1.20.UC2 spatial.8.21.UC3 

bts.2.00 ifxrltree.2.00 mqblade.2.0 web.4.13.UC4 

ifxbuiltins.1.1 krakatoa Node.2.0 wfs.1.00.UC1 

If you do not see the DataBlade directory reference for the one you want, you 

must acquire it by way of a download or CD. 

Installation on UNIX is simply a matter of uncompressing the new DataBlade 

module into a temporary directory. After the files are expanded, run the 

installation script, ./install. The ./install script creates a new module 

directory under the INFORMIXDIR/extend directory. Some file expansions can 

result in more than one new module. If there is more than one module, you must 

run the ./install script for each one. 

Installation on Windows systems requires that you go to the installation location 

and run setup.exe. Select the Typical installation option. The other dialog 

verification is the INFORMIXDIR location. With those items confirmed, the 

software is installed. When the installation is complete, the module directory is 

installed in the INFORMIXDIR\extend directory. 

Registering the DataBlade 

With a DataBlade directory in place, the active database server is not aware of 

the DataBlade directories until the software is registered in the database. 

Registration is the process of executing the SQL statements that create the 

DataBlade module database objects and identify the DataBlade module shared 

object file or dynamic link library to the database server. 


With the release of 11.50.XC4, IBM Informix provides the following distinct 

methods for DataBlade registration: 

► BladeManager 

Available with the first release of datablades, the BladeManager is an 

interface that automates the registration process by performing a series of 

SQL steps in the database engine. 

► sysbldprepare() 

This command is an Informix function for DataBlade registration. At its 

simplest, you can run the command inside dbaccess with your target 

database open to install a DataBlade. It has a few restrictions that are 

described in IBM Informix DataBlade Module Installation and Registration 

Guide, Version 4.20, G229-6368. To register the bts DataBlade with this 

interface, use the following command: 

EXECUTE FUNCTION sysbldprepare('bts.*','create'); 

To register a DataBlade module using BladeManager: 

1. Start BladeManager: 

– On UNIX or at the MS-DOS prompt, the BladeManager is started with the 

blademgr command. 

– To start BladeManager on a Windows system, select Start � Programs � 

Informix program group name � BladeManager or double-click the 

BladeManager icon in the Informix program group. 

If the BladeManager fails to start, it is either not installed or you do not have 

the environment variables set, as noted in the previous section. 

2. Set confirmations. 

If you want an automatic confirmation after each step, turn the prompt on: 

set confirm on 

Commands run when you press the carriage return. 

3. Connect to an Informix instance: 

show servers 

set server demo_on < Use you own server name for demo_on> 

If you want to connect as a different user, try: 

set user 

At the password prompt, enter your password. Validation does not occur until 

connection, on the next step. 


To connect to a database, run one of the following commands: 

list stores 

register module_name database_name 

unregister module_name database_name 

The module_name represents the name of the DataBlade module directory. 

These names typically follow the form of the DataBlade module name 

followed by the version number. 

When BladeManager registers a DataBlade module, it executes a series of SQL 

CREATE statements to register each database object in the module. You must 

have resource permissions on the database to register the DataBlade. In 

addition, if your server has implemented the ONCONFIG EXTEND role, you 

must be granted the EXTEND role by user informix. 

If the registration of a module fails, BladeManager returns the database to its 

prior state. To see the SQL statements that failed, look at the corresponding log 

file and check the procedure in Appendix A. Troubleshooting Registration 

Problems of IBM Informix DataBlade Module Installation and Registration Guide, 

Version 4.20, G229-6368, for possible solutions. 

Occasionally, DataBlade modules have more than one interface. If there are 

additional modules, there are also dependencies. You have to make sure that 

each of the interfaces are registered correctly in order for the DataBlade to work. 

BladeManager automatically checks for dependencies and registers any 

dependencies it might need. If the BladeManager cannot do the registration, it 

will prompt you to do so manually. 

Important: BladeManager does not verify the integrity of DataBlade modules 

that have additional interfaces, nor does it not check for the presence of 

required database objects. 

Datablade modules written in the Java language can only be registered in IBM 

Informix Servers with J/Foundation database servers. 


10.3.2 IBM Informix provided DataBlades 

Table 10-2 the DataBlades that are available with IBM Informix database servers. 

Table 10-2 Informix provided DataBlades 


DataBlade 

module name Description Special notes 

Large Object 

Locator 

A foundation Datablade module for large 

objects management that can be used by 

other modules that create or store 

large-object data. 

MQ DataBlade Allows IBM Informix database 

applications to communicate with other 

MQSeries® applications with MQ 

messaging. 

Binary DataBlade This module includes binary data types to 

store binary-encoded strings that can be 

indexed for quick retrieval. 

Basic Text Search Permits text search of words and phrases 

in an unstructured document repository 

stored in a column of a table. 

Node DataBlade This module is for the hierarchical data 

type, to represent hierarchical data within 

a relational database. 

Web Feature 

Service 

J/Foundation 

krakatoa 

This module is an add-on to allow Open 

Geospatial Consortium (OGC) web 

feature service as a presentation layer for 

the Spatial and Geodetic DataBlade 

modules 

A library of classes and interfaces that 

allow programmers to create and execute 

Java UDRs that access Informix database 

servers 

ifxbuilt-ins This is not really a DataBlade, but it sets 

up definitions and functions for the 

standard data types offered in the informix 

server. 

ifxmngr.2.00 This is the API that supports the 

BladeManager. 

Available on 

standard install 

(LLD.1.20.UC2) 

Available on 


(mqblade.2.0) 

Available on 

standard install. 

(binaryudt.1.0) 

Available on 


(bts.2.00) 

Available on 


(Node.2.0) 

Available on 


(wfs.1.00.UC1) 

Available as a part 

of Informix Server 

with J/Foundation 

Available on 


(ifxbuiltins.1.1) 

Available on 

standard UNIX 

install 



DataBlade 


ifxrltree.2.00 This is a foundational, multidimensional, 

index called “Region tree” (R-tree) (also 

known as Range Tree). This blade is 

needed for both spatial and time related 

data management. 

Image Foundation This module is a foundation DataBlade 

which provides a base on which new or 

specialized image types and image 

processing technologies can be added or 

changed. Because the foundation is open, 

secure, and scalable, it provides a clear 

path toward reusing and repurposing 

valuable image assets. 

Excalibur Text 

Search 


This module enables provides extensive 

text-searching capabilities; It supports 

full-text indexing, including extensive 

fuzzy-search logic for indexing scanned 

text. Can search document types 

including: ASCII, Word, Excel, HTML, 

PowerPoint, WordPerfect, and PDF. 

Includes an adaptive pattern recognition 

process (APRP) and capabilities such as 

multiple stop-word lists, proximity 

searching and synonym lists. 

Geodetic This blade supports global space- and 

time based queries. It is designed to treat 

earth as a globe rather than a flat plane. 

Supports client-side Geographic 

Information Systems (GIS) software. 

Spatial This blade transforms locations and 

traditional 2-d map data into useful 

information. Uses SQL-based spatial data 

types and functions that can be used 

directly through standard SQL queries or 

with client-side Geographic Information 

Systems (GIS) software. 

Available on 


No charge 

download 

License fee applies 


No charge 

download


DataBlade 


TimeSeries This module supports data for managing 

time-series and temporal data. A “time 

series” is any set of data that is accessed 

in sequence by time and can be 

processed and analyzed in a 

chronological order. 

Video Foundation This blade allows you to incorporate video 

servers, external control devices, 

compression codes, and cataloging tools 

to manage video content and metadata or 

information about the content. Allows 

metadata elements in the database, while 

allowing video content to be maintained 

on disk, video tape, video server, or other 

external storage devices. 

Web This module supports most web server 

APIs and has a web client application to 

build and run SQL queries to work with 

your database. Enables customized web 

applications. Allows you to track 

persistent session variables between 

AppPages. 

10.3.3 Developing a bladelet routine 

License fee 

applies. 

License fee 

applies. 


We can define a bladelet as a small, unofficial DataBlade module. It is meant to 

be useful (and complete with source code) from the time you set it up, but it 

becomes your own application (with no support or warranty). If you have tried out 

our UDR development examples, you have a bladelet. 

As you might have observed from having to drop and re-create the JAR API in 

the server in our earlier example, you can understand that if you have a large 

number of UDRs and have gone to the trouble of creating user-defined data 

types, the whole package of tasks that are required to set up, change, or update 

a DataBlade object inside the server might not be a convenient task. 

On a large scale, if you have API dependencies, dozens of UDRs, and other 

DataBlade related objects, you will want to move them and install them as a 

package. IBM Informix provides a Windows-based interface for this, which has 

the ability to do the package preparation work for you. The package preparation 


interface, called BladeSmith, allows you to populate a properties definition 

dictionary. 

When the properties are all defined and you proceed, BladeSmith creates, 

assembles, and arranges a directory structure with a complete tree layout of all 

the components that are required and handled in a DataBlade registration 

process. The resulting directory tree layout and assembly pieces provide a 

prepared package that is ready to ship to an operating system of your choice. 

Likewise, any language source code that is output for the preparation task is 

parcelled out for the appropriate component nodes also. 

The dispensation for the BladeSmith file components and directory structure is 

laid out based on the type of component node, as described in Table 10-3. 

Table 10-3 BladeSmith file package creation layout 

Component node What is generated 

Source All source code in the coding languages you use for your 

DataBlade module objects 

Client Client code (ActiveX or Java) 

Server Server code in the coding language you specified for BladeSmith 

Individual language Source code for the represented language (C, Java, or SPL) 

For further information about creating datablade objects using BladeSmith 

generating files, refer to: 


dbdk.doc/sii-smith-27272.htm 

For further information or examples of existing bladelets and downloads 

developed by users, refer to: 

http://www.ibm.com/developerworks/data/zones/informix/library/samples/db_downlo 

ads.html 

There is also a downloads page that features bladelets at the International 

Informix Users Group site called “ORDBMS - Object-Relational Database 

Extensibility, DataBlades” at: 

http://www.iiug.org/software/index_ORDBMS.html 


Chapter 11. Working with Ruby on Rails 

This chapter contains information about how to develop applications against an 

IBM Informix database using the Ruby programming language and the Ruby on 

Rails web development framework. 

In this chapter, we discuss the following topics: 

► A brief overview of Ruby on Rails 


► Database operations 

► Using the Rails Adapter with Ruby Informix 

► Using the Rails Adapter with IBM_DB 

11 


11.1 A brief overview of Ruby on Rails 

Ruby is a open source programming scripting language with a focus on simplicity 

and productivity. Ruby is similar to other scripting languages like Perl or Python 

with the difference that Ruby is an object-oriented language. Ruby is both 

technology- and platform-independent. You can find implementations of the Ruby 

run time on C, Java, and even .NET, making Ruby a useful option for any 

scripting need. 

For more information about the Ruby language, refer to: 

http://www.ruby-lang.org/en/about/ 

Rails is an open source Ruby framework for developing database-backed web 

applications. Rails expands the object-orientated core design of Ruby, helping 

developers to build websites and applications with minimum coding efforts. 

Rails is based on two key principles: 

► Convention over configuration (CoC), where developers need to focus only 

on the exceptions to the conventions. Every other aspect of the application, 

from design to implementation, is done automatically by the defined 

conventions. 

The conventions define rules such as use a plural for the table names. For 

example, if the application uses an entity called Book, the table that stores 

this entity must be called Books, and if it stores details about a Person, the 

table must be called People. 

► Don’t Repeat Yourself (DRY). Information is located in one place only. 

Database object definitions, documentation, and configuration scripts all are 

kept in one location and are consulted when information about them is 

required. 

For more information, refer to: 

http://rubyonrails.org/documentation 


11.1.1 Architecture of Ruby on Rails 

Ruby on Rails is built with the Model, View, Controller (MVC) architecture that is 

typically used in web-based GUI programming. This architecture has three main 

concepts: 

► Model 

The business logic of the system, which encompasses the persistence layer 

because it interacts with a database back end. 

► View 

The GUI interface of the model that is visible to the user. One Model can have 

many views. 

► Controller 

The action taken by the user using the view. The controller takes inputs from 

the user through the view and executes the business logic encapsulated in 

the model. 

The Rails framework provides a set of utilities and components that are designed 

to facilitate the development of web applications: 

► Rake is a build tool that is bundled with the Ruby programming language. It is 

the equivalent to the make command on UNIX. 

► WEBrick is the web server that is bundled with Ruby on Rails. 

► ActiveRecord is the object-relational mapper of Rails and provides for 

persistence. It presents the database table as a class, which in Rails is called 

model. 

► Action Controller is the component that manages the controllers in a Rails 

application. It also processes and dispatches incoming requests. 

► Action View manages the views in a Rails application. 

11.1.2 Ruby Driver and Rails Adapter 

IBM Informix supports database access for client applications written in the Ruby 

programming language and web application development with the Rail 

framework. 

Ruby Driver 

To use an database with Ruby, the application requires a Ruby driver. This driver 

provides the layer that connect the Ruby run time with the database server. 

Chapter 11. Working with Ruby on Rails 363

The following drivers allow Ruby to connect to an IBM Informix database: 

► The Ruby Informix driver is an open source project supported by the open 

source community. It allows Ruby to connect to any IBM Informix database 

server. The Ruby driver is developed using the IBM Informix ESQL/C 

language that provides full support for all the Informix database features and 

data types. Because it uses the Informix Client Software Development Kit 

(Client SDK) libraries, 

► Ruby Driver for IBM Data Servers driver (IBM_DB) is provided, supported, 

and developed by IBM as an open source project. The Ruby driver is bundled 

together with the Rails Adapter in the Rails Adapter/Driver for IBM Data 

Servers package. 

Rails Adapter 

A Rails Adapter is a Ruby script that allows you to use a specific Ruby driver 

within the Rails framework. It provides the required Ruby objects, for example the 

ActiveRecord object, that enable the full use of the Ruby driver inside the Rails 

framework. 

IBM Informix supports the following Rails adapters: 

► informix_adapter.rb, used in conjunction with the Ruby Informix driver. 

Requires Client SDK libraries for the communication with the Informix 


► ibm_db_adapter.rb, used with the Ruby Driver for IBM Data Servers. 

Requires the IBM Data Server Driver for ODBC and CLI package. 

Both adapters are available from the Ruby repository as Ruby gems. Ruby gems 

are self-contained packages that contain all the libraries, source files, and scripts 

needed for the Ruby component. 


This section describes how to set up and configure both Ruby drivers and Rails 

adapters for use with an IBM Informix database. 

11.2.1 Ruby Informix driver 

The Ruby Informix driver is available for download at the SourceForge website at: 

http://rubyforge.org/projects/ruby-informix 


You can use the Ruby gem utility to download the Ruby Informix driver 

automatically from the Ruby repository and install it in the Ruby environment. 

Run the following command from your Ruby session to install the Ruby Informix 

driver: 

gem install ruby-informix 

Because the driver shared library, informixc.so, is built during the installation 

process, the environment should contain the correct settings for compiling 

ESQL/C applications. Refer to Chapter 4, “Working with ESQL/C” on page 125 

for more information about ESQL/C settings. 

You can find more information about the installation process in the README file 

inside the gem directory. See Example 11-1 for the list of files that are included 

with the Ruby Informix driver. 

Example 11-1 The gem directory 

Directory of C:\work\Ruby187\lib\ruby\gems\1.8\gems\ruby-informix-0.7.3 

03/07/2010 19:34 . 

03/07/2010 19:34 .. 

03/07/2010 19:19 8,383 Changelog 

03/07/2010 19:19 1,470 COPYRIGHT 

03/07/2010 19:29 ext 

03/07/2010 19:35 lib 

03/07/2010 19:19 4,500 README 

03/07/2010 19:19 test 



Configuration 

The Ruby Informix uses the same connectivity information as other Client SDK 

components. It uses the INFORMIXDIR environment variable to locate the 

libraries and resources such as error message files or configuration files. 

By default, the Ruby driver connects to the database server specified in the 

INFORMIXSERVER environment variable. Same as the other Client SDK 

components, the information regarding the INFORMIXSERVER value is stored 

on the sqlhosts file or the Windows registry. For more information, refer to 

“Connectivity on UNIX” on page 27. 

The shared library search path variables, for example, LD_LIBRARY_PATH or 

SHLIB_PATH, must contain the $INFORMIX/libl and $INFORMIX/lib/esql 

directories. Otherwise, the Ruby driver might fail to load the ESQL/C libraries that 

it requires for work. 


Data types 

The Ruby Informix driver provides the data types to be used against an IBM 

Informix database. The driver provides specific types such as 

Informix::IntervalYTM or Informix::Slob to handle specific Informix types. 

Table 11-1 shows the data type mapping between the Ruby Informix driver and 

the Informix database. 

Table 11-1 Ruby Informix data type mapping 

Informix data type Ruby data type 

SMALLINT, INT, INT8, FLOAT, SERIAL 

and SERIAL8 

CHAR, NCHAR, VARCHAR, 

NVARCHAR 

Verifying connectivity 

Ruby includes an interactive shell called irb that you can use to run simple Ruby 

statements. The irb is located in the bin directory of the Ruby installation. 

The driver name used inside the Ruby scripts to reference the Ruby Informix 

driver is informix. 

To test whether the Ruby driver can connect to a database, you must load the 

Ruby driver and then create a connection using the Ruby Informix object. 


Numeric 

String 

DATE Date 

DATETIME TIME 

INTERVAL Informix::IntervalYTM, Informix::IntervalDTS 

DECIMAL, MONEY BigDecimal 

BOOL TrueClass, FalseClass 

BYTE, TEXT StringIO, String 

CLOB, BLOB Informix::Slob

Example 11-2 demonstrates how to load the Ruby Informix driver and connect to 

an IBM Informix database. The fist command, require 'informix', tells the 

Ruby run time to load the Ruby Informix driver. After that, it creates a Ruby 

Informix connection object and prints the database version information. 

Example 11-2 Testing connection with Ruby informix 

C:\work>irb 

irb(main):001:0> require 'informix' 

=> true 

irb(main):002:0> db=Informix.connect('stores_demo','informix','password') 

=> # 

irb(main):003:0> puts db.version 

IBM Informix Dynamic Server Version 11.50.FC6 

=> nil 

irb(main):004:0> 

11.2.2 Data Server Ruby driver 

The Data Server Ruby driver uses the Data Server CLI driver to connect the 

Informix database. It uses the DRDA protocol so the version of the IBM Informix 

database server must be 11.10 or 11.50. 

The driver is included with IBM Data Server Driver and is also available to 

download directly from the RubyForge website: 

http://rubyforge.org/projects/rubyibm/ 

You can install the complete package using the Ruby gem utility by running the 

following command from a Ruby session: 

gem install ibm_db 

For information about the build and setup process for Data Server Driver, consult 

the README file in the driver directory. 

Example 11-3 shows the Data Server Ruby driver directory. 

Example 11-3 The ibm_db gem directory 

Directory of C:\work\Ruby187\lib\ruby\gems\1.8\gems\ibm_db-0.10.0-x86-mswin32 

03/07/2010 17:30 . 

03/07/2010 17:30 .. 

03/07/2010 17:30 6,063 CHANGES 

03/07/2010 17:30 ext 

03/07/2010 17:30 1,656 init.rb 

03/07/2010 18:06 lib 


03/07/2010 17:30 1,088 LICENSE 

03/07/2010 17:30 299 MANIFEST 

03/07/2010 17:30 13,402 README 

03/07/2010 17:30 test 



You can find additional information regarding the Ruby driver for IBM Data 

Servers at: 

http://publib.boulder.ibm.com/infocenter/db2luw/v9r5/topic/com.ibm.db2.luw.apdv 

.ruby.doc/doc/t0052765.html 

On some platforms, such as Windows operating system platforms, the shared 

library for the Ruby driver is already included in the package. Therefore, there is 

no need for a C build environment. 

Example 11-4 shows the Ruby driver directory from Data Server Client on a 

Windows system after the installation. 

Example 11-4 Windows system Data Server Ruby directory 

C:\work>dir "C:\Program Files\IBM\IBM DATA SERVER DRIVER\ruby" 



Directory of C:\Program Files\IBM\IBM DATA SERVER DRIVER\ruby 

17/05/2010 02:16 . 

17/05/2010 02:16 .. 

30/05/2009 11:09 198,144 ibm_db-0.10.0-mswin32.gem 



C:\work> 

Configuration 

The Data Server Ruby driver uses the Data Server ODBC/CLI driver for the 

connection to the database. 

The configuration details are the same as with the ODCB/CLI driver. These 

details are usually kept in the db2profile.ini file. Refer to 2.2.3, “Setting up IBM 

Data Server drivers” on page 43 for detailed information about Data Server 

Driver configuration. 


11.2.3 Rails adapters 

Data types 

There are no specific Ruby objects to use Informix data types. Data Server Ruby 

driver supports the same Informix data types as Data Server Driver for CLI. 

Verifying connectivity 

We use an irb session to test the connectivity against an IBM Informix database 

server. 

The reference name of the Data Server Ruby driver is ibm_db. You must load this 

driver before creating the Ruby connection object. 

Example 11-5 shows how to load the Ruby driver and how to connect to the 

Informix server. 

Example 11-5 Testing connection with data server Ruby driver 

C:\work>irb 

irb(main):001:0> require 'mswin32/ibm_db' 

=> true 

irb(main):002:0> db=IBM_DB.connect 'dsc_dsn','informix','password' 

=> # 

irb(main):003:0> 

First, load the Ruby driver with require 'mswin32/ibm_db'. Then, open the 

connection using the IBM_DB::connect method. 

Note: Because we use the Windows version of the Ruby driver, we must prefix 

the driver name with the mswin32 directory. 

You can also made a dsn-less connection by specifying all the required 

parameters in the connection string as follows: 

IBM_DB.connect 'DRIVER={IBM DB2 ODBC DRIVER};DATABASE=stores_demo; 

HOSTNAME=kodiak;PORT=9089;PROTOCOL=TCPIP;UID=informix;PWD=password;', '', '' 

The Ruby Informix Rails Adapter provides the Ruby ActiveRecord object that 

makes the use of the Ruby driver to work on the Rails framework possible. 

The Rails Adapter for the Ruby Informix driver is a free download that is available 

at: 

http://rubyforge.org/projects/rails-informix/ 


The Rails Adapter can be installed automatically as a Ruby gem using the gem 

utility. Example 11-6 shows how to install the Ruby Informix adapter. 

Example 11-6 Installing the Ruby Informix adapter 

C:\work>gem install activerecord-informix-adapter -v 1.1.1 

Successfully installed activerecord-informix-adapter-1.1.1 

1 gem installed 

Installing ri documentation for activerecord-informix-adapter-1.1.1... 

Installing RDoc documentation for activerecord-informix-adapter-1.1.1... 

C:\work> 

The configuration of the adapter depends on the version of Rails that is installed 

in the Ruby environment. On versions older than 2.x, you need to copy the 

informix_adapter.rb adapter script file into the connection_adapters directory. 

Example 11-7 shows the connection_adapter directory with both Rails adapters 

installed. 

Example 11-7 The connection _adapter directory 

Directory of 

C:\work\Ruby187\lib\ruby\gems\1.8\gems\activerecord-1.15.6\lib\active_record\co 

nnection_adapters 

3/07/2010 18:02 . 

3/07/2010 18:02 .. 

3/07/2010 17:01 abstract 

3/07/2010 17:01 5,235 abstract_adapter.rb 

3/07/2010 17:01 6,957 db2_adapter.rb 

3/07/2010 17:01 27,749 firebird_adapter.rb 

3/07/2010 17:01 30,751 frontbase_adapter.rb 

3/07/2010 17:30 70,854 ibm_db_adapter.rb 

3/07/2010 20:06 9,916 informix_adapter.rb 

3/07/2010 17:01 13,774 mysql_adapter.rb 

3/07/2010 17:01 11,531 openbase_adapter.rb 

3/07/2010 17:01 25,897 oracle_adapter.rb 

3/07/2010 17:01 21,513 postgresql_adapter.rb 

3/07/2010 17:01 13,162 sqlite_adapter.rb 

3/07/2010 17:01 22,087 sqlserver_adapter.rb 

3/07/2010 17:01 22,622 sybase_adapter.rb 




When using versions of Rails older than 2.x, it is also required to include the 

reference name of the Ruby driver in the RAILS_CONNECTION_ADAPTER 

parameter in the ActiveRecord Ruby script (see Example 11-8). 

Example 11-8 The active_record file 

C:\work\Ruby187\lib\ruby\gems\1.8\gems\activerecord-1.15.6\lib>grep informix 

active_record.rb 

RAILS_CONNECTION_ADAPTERS = %w( mysql postgresql sqlite firebird sqlserver 

db2 oracle sybase openbase frontbase informix ibm_db ) 

C:\work\Ruby187\lib\ruby\gems\1.8\gems\activerecord-1.15.6\lib> 

After creating a Rails project, you must update the project configuration file that 

contains the database information, database.yml, with the connection details of 

the IBM Informix database. This file is located in the /config directory 

and has three sections: 

► Development 

► Test 

► Production 

These sections point to databases on the respective environments. The 

database connectivity properties include: 

► adapter: The Ruby driver used. You do not have to give the complete version. 

► database: Database to which to connect. 

► username and password: To connect to the Informix server. 

► server: The system on which the Informix server is running. 

► port: The DRDA port on the Informix server. 

Example 11-9 shows a typical database.yml file with the details for an IBM 

Informix database. The Rails application is named stores7, and we connect to 

an Informix server called demo_on. 

We use the Ruby Informix driver reference name for the adapter parameter 

informix. The server parameter identifies the Informix server to connect to. The 

information about the Informix server, such as host and port, is retrieved from the 

sqlhosts file or Windows registry. 

Example 11-9 The database.yml file for the Ruby informix Adapter 

C:\work\stores7\config>type database.yml 

development: 

adapter: informix 

database: stores7 

pool: 5 

timeout: 5000 


server: demo_on 

username: informix 

password: password 

# Warning: The database defined as 'test' will be erased and 

# re-generated from your development database when you run 'rake'. 

# Do not set this db to the same as development or production. 

test: 

adapter: mysql 


username: root 

password: 

host: localhost 

production: 



pool: 5 

timeout: 5000 




C:\work\stores7\config> 

Rails Adapter for IBM Data Server 

The Rails Adapter for the IBM Data Server Ruby driver is bundled with the Ruby 

driver. It is installed when the Ruby driver is installed. 

In the same way as with the Ruby Informix Rails Adapter, if the Rails Adapter for 

IBM Data Server is installed on a version of Rails older than 2.x, the adapter 

script (informix_adapter.rb) must be copied in the connection_adapter 

directory, and the RAILS_CONNECTION_ADAPTER parameter in the 

active_record.rb Ruby script has to be updated. 

The database configuration file for a Rails project, database.yml, has to be 

updated with the details for the Informix server. 

Example 11-10 shows a database.yml file that is used in a Rails project that 

connects to an IBM Informix database. 

Example 11-10 The database.yml file for the Rails Adapter for IBM Data Servers 

C:\work\stores7\config>type database.yml 

development: 

adapter: ibm_db 



pool: 5 

timeout: 5000 

host: kodiak 

port: 9089 






test: 




password: 


C:\work\stores7\config> 

The adapter parameter is set to the reference name of the Data Server Ruby 

driver ibm_db. It also contains the host name and the port parameter with the 

details about the DRDA Informix instance. These details are the same as used in 

the Data Server driver for ODBC/CLI. 

For a list of all the parameters, refer to: 


ent.ruby.doc/doc/t0052780.html 

11.3 Database operations 

This section provides examples of using both Ruby drivers to perform basic 

operations against an IBM Informix database server. It also demonstrates how to 

use the Rails Adapter to create basic web applications. 


Using Ruby Informix driver 

In this section, we discuss the basic database operation using the Ruby Informix 

driver. 

Connection to the database 

Example 11-11 shows how to connect to an Informix database. The database 

name, user name, and password are passed as the parameters in the command 

line. 

Example 11-11 The ifx_connect.rb output 

C:\work>type ifx_connect.rb 

# load the informix driver 

require 'informix' 

# Connect to the database 

db = Informix.connect(ARGV[0],ARGV[1],ARGV[2]) 

# print database information 

print "Connected to #{db.version}" 

db.close 

C:\work>ruby ifx_connect.rb stores_demo informix password 

Connected to IBM Informix Dynamic Server Version 11.50.FC6 

C:\work> 

Getting information about a table 

Example 11-12 demonstrates how to use the Ruby connection object to retrieve 

metadata information about the state table. It uses the columns() method of the 

Informix connection object to retrieve a Ruby array with all the metadata 

information. 

Example 11-12 The ifx_metadata.rb output 

C:\work>cat ifx_metadata.rb 




db = Informix.connect(ARGV[0]) 


print "Connected to #{db.version}\n" 

db.columns(ARGV[1]).each { 

|name| name.each {|elem| print " #{elem[0]} #{elem[1]}\n"} 

} 

db.close 

C:\work>ruby ifx_metadata.rb stores_demo state 


precision 0 


type 0 

scale 0 

length 2 

xid 0 

nullable true 

name code 

stype CHAR 

... 

Executing a simple SQL statement 

Using the Ruby driver, you can run an SQL statement directly from the Ruby 

connection object or through a prepared statement object. 

Example 11-13 demonstrates how to run a simple SQL statement using a 

prepared statement Ruby object. The execute() method returns the number of 

affected rows. 

Example 11-13 The ifx_execute.rb output 

C:\work>cat ifx_execute.rb 




db = Informix.connect(ARGV[0]) 



# create a prepare object with the SQL passed 

stmt = db.prepare(ARGV[1]) 

# Execute the prepared statement 

rc=stmt.execute() 

print "Result=#{rc}" 

db.close 

C:\work>ruby ifx_execute.rb stores_demo "DELETE from STATE where CODE='AR'" 


Result=1 

C:\work> 


If the SQL statement returns only one row, you can use the execute() method to 

retrieve that value (see Example 11-14). 

Example 11-14 The ifx_execute.rb output 

C:\work>ruby ifx_execute.rb stores_demo "SELECT sname FROM state WHERE 

code='CA'" 


Result=snameCalifornia 

C:\work> 

Using parameters 

Example 11-15 shows how to prepare and execute a parametrized INSERT 

statement using the Ruby driver. 

Example 11-15 The ifx_parameters output 

C:\work>cat ifx_insert.rb 




db = Informix.connect('stores_demo') 




stmt = db.prepare('INSERT INTO state(code,sname) VALUES (?,?)') 

# Execute the statement using parameters 

rc=stmt.execute(ARGV[0],ARGV[1]) 



db.close 

C:\work>ruby ifx_insert.rb AR Arizona 


Result=1 

C:\work> 


Selecting data from the database 

When selecting multiple records from the database the application must create a 

cursor object to fetch the selected rows. Example 11-16 illustrates how to return 

information using an Informix cursor. 

Example 11-16 The ifx_cursor.rb output 

C:\work>cat ifx_cursor.rb 




db = Informix.connect('stores_demo') 

# display database information 


# Create a Cursor object 

cur = db.cursor(ARGV[0]) 

# Open the cursor and fetch some rows 

cur.open.each {|rows| 

puts rows*" = " 

}.close 

# Close connection 

db.close 

C:\work>ruby ifx_cursor.rb "SELECT FIRST 3 sname FROM state" 


Alaska 

Hawaii 

California 

C:\work> 

Using the Ruby Informix IfxSlob class 

The Slob class is the Ruby interface for handling smart large objects. It provides 

methods for every action applicable with a smart large object. By using the 

Informix::Slob class, it is possible to perform the same operations against a 

smart large object as with other programming languages and drivers. The Slob 

methods such as Seek() or Lock() allow random I/O to individuals part of the 

large object that can only be achieved using this Ruby driver. 


Example 11-17 shows how to select a BLOB from a database table. It retrieves 

the catalog_advert CLOB column from the catalog table and prints out the 

content of the large object and the size of the large object. 

Example 11-17 The ifx_blob.rb output 

C:\work>cat ifx_blob.rb 




db = Informix.connect("stores_demo") 

# Creates an Informix Slob object 

slob = Informix::Slob 

# Opens a cursor to retrieve 

cur = db.cursor("SELECT catalog_num,advert_descr FROM catalog WHERE 

catalog_num=?") 

cur.open(ARGV[0]).each {|rows| 

slob = rows[1].open 

print "Number = #{rows[0]}\n" 

# Reads the blob data as a String 

print "Clob data= #{rows[1].read(rows[1].size)}\n" 

print "Clob Size= #{rows[1].size}\n" 

# Close the Slob object 

slob.close 

} 

# Close database connection 

db.close 

C:\work> 

C:\work>ruby ifx_blob.rb 10001 

Number = 10001 

Clob data= Brown leather. Specify first baseman's or infield/outfield style. 

Clob Size= 98 



Clob data= 

Double or triple crankset with choice of chainrings or chunky bacon. For double 

crankset... 

Clob Size= 154 



Clob data= No buckle so no plastic touches your chin. Meets both ANSI and 

Snell... 

Clob Size= 123 

C:\work> 


For examples and a full description of all the method implemented by the 

Informix::Slob class, refer to: 

http://ruby-informix.rubyforge.org/doc/classes/Informix/Slob.html 

Using the Ruby Informix INTERVAL 

The Ruby Informix driver provides a specific class to deal with the Informix 

INTERVAL data type. 

Example 11-18 shows how to define and use the Informix::Interval class. In 

this example we create an Interval Year to Month with one year and one month 

as the value. The code performs a simple arithmetic operation adding the Interval 

to the current date. 

Example 11-18 The ifx_interval.rb output 

# Creates an Informix Interval object 

minterval = Informix::Interval.year_to_month(1, 1) 

print "Interval \t=#{minterval}\n" 

today = Date.today 

print "Current date \t=#{today}\n" 

print"Interval+today\t=#{minterval + today}\n" 

C:\work>ruby ifx_interval.rb 

Interval =1-01 

Current date =2010-07-04 

Interval+today =2011-08-04 

C:\work> 

You can fine the full documentation about all the methods supported by the Ruby 

Informix driver at: 

http://ruby-informix.rubyforge.org/doc/ 

Using Data Server Ruby driver 

In this section, we discuss the basic database operation using the Data Server 

Ruby driver. 

Connecting to the database 

The syntax for opening a connection with an Informix database server using the 

Data Server Ruby driver differs from the syntax used by the Ruby Informix driver. 


Example 11-19 shows a simple Ruby script that creates a connection object and 

opens the connection. In the example code we also retrieve information about 

the Informix server using the IBM_DB::server_info class. 

Example 11-19 The dsc_connect.rb script 

C:\work>cat dsc_connect.rb 


require 'mswin32/ibm_db' 


db = IBM_DB.connect(ARGV[0],ARGV[1],ARGV[2]) 

info = IBM_DB.server_info(db) 


print "Connected to #{info.DBMS_NAME} #{info.DBMS_VER}" 

C:\work>ruby dsc_connect.rb testdsc informix password 

Connected to IDS/NT64 11.50.0000 

C:\work> 

The Data Server Ruby driver is based on calls to the CLI driver, this means it 

takes the connection details from the db2cli.ini configuration file. 

Example 11-20 shows the contents of the db2cli.ini file that we used for this 

test. 


C:\work>type "c:\Documents and Settings\Administrator\db2cli.ini" 

[dsc_dsn] 


Port=9089 



PWD=password 

UID=informix 

C:\work> 


Executing an SQL statement 

Example 11-21 demonstrates how to execute an SQL statement using the 

prepare() and execute() methods of the IBM_DB driver. Both methods, 

prepare() and execute(), require the connection and statement objects as 

parameters. 

Example 11-21 The dsc_execute.rb output 

C:\work>cat dsc_execute.rb 




db = IBM_DB.connect(ARGV[0],'','') 



print "Connected to #{info.DBMS_NAME} #{info.DBMS_VER}\n" 


stmt = IBM_DB.prepare(db,ARGV[1]) 


rc=IBM_DB.execute(stmt) 


C:\work>ruby dsc_execute.rb dsc_dsn "DELETE from STATE WHERE code='NW'" 


Result=true 

C:\work> 

Parametrized SQL statement 

When using parameters for an SQL statement, the application can use the 

execute() method. You can provide the parameters as a second argument for 

the method call. 

Example 11-22 insert a new record into the state table with the values passed to 

the script through the command line. 

Example 11-22 The dsc_param.rb output 

C:\work>cat dsc_param.rb 




db = IBM_DB.connect('dsc_dsn','','') 




sql = 'INSERT INTO state(code, sname) VALUES (?,?)' 


# create a prepare object 

stmt = IBM_DB.prepare(db,sql) 

# display Statement and parameters 

print "SQL=#{sql}\n" 


rc=IBM_DB.execute(stmt,[ARGV[0],ARGV[1]]) 


C:\work> 

C:\work>ruby dsc_param.rb "NW" "NewState" 


SQL=INSERT INTO state(code, sname) VALUES (?,?) 

Result=true 

C:\work> 

Selecting data 

The Data Server Ruby driver has several methods that allow retrieving data from 

the database, such as fetch_array(), fetch_assoc(), and fetch_row(). 

Example 11-23 shows a simple Ruby script that returns the first two columns of 

an SQL SELECT statement passed through the command line. The script uses 

the fecth_array() method to retrieve the rows as an array object. 

Example 11-23 Select data using fetch_array() 

C:\work>cat dsc_fetch.rb 




db = IBM_DB.connect(ARGV[0],'','') 





stmt = IBM_DB.prepare(db,ARGV[1]) 


IBM_DB.execute(stmt) 

while row = IBM_DB.fetch_array(stmt) 

puts "#{row[0]}:#{row[1]}" 

end 

C:\work>ruby dsc_fetch.rb dsc_dsn "SELECT FIRST 3 code,sname FROM state" 


AK:Alaska 

HI:Hawaii 

CA:California 

C:\work> 


Using smart large objects 

The Data Server Ruby driver handles smart large objects as normal data types. It 

does not support all the smart features that are normally available with other 

drivers. However, it simplifies the code that is needed to deal with these data 

types. 

Example 11-24 retrieves a CLOB column from the catalog table and displays the 

contents. 

Example 11-24 The dsc_blob.rb file 

C:\work>cat dsc_blob.rb 




db = IBM_DB.connect('dsc_dsn','','') 





sql = "SELECT catalog_num,advert_descr FROM catalog WHERE catalog_num=?" 

stmt = IBM_DB.prepare(db,sql) 


IBM_DB.execute(stmt,ARGV) 

while row = IBM_DB.fetch_array(stmt) 

puts "#{row[0]}:#{row[1]}" 

end 

C:\work>ruby dsc_blob.rb 10001 


10001:Brown leather. Specify first baseman's or infield/outfield style. 

Specify right- or left-handed. 

C:\work> 

You can find additional documentation about the methods for the Ruby for IBM 

Data Server at: 

http://rubyibm.rubyforge.org/docs/driver/2.0.0/doc/ 

You can also find information in the IBM DB2 Information Center: 


ent.ruby.doc/doc/c0052760.html 


11.4 Using the Rails Adapter with Ruby Informix 

In this section, we demonstrate how to create a basic web application using the 

Rails framework with the Ruby Informix Adapter. 

One of the key concepts of Rails is Convention over Configuration, meaning that 

you must follow the convention rules when designing your database so that the 

Rails framework can generate code automatically to handle typical operations 

with the database. 

The following convention rules are required by the Rails framework: 

► Table name must be a plural name for the entity it contains. For example, if 

the table contains information about books, it should be called Books. 

► The table must contains an unique primary key column and should be called 

ID. 

► You must create an Informix SQL SEQUENCE for each of the tables used for 

both Ruby drivers. The name of the sequence must be tablename_seq. 

You can find additional information about Rails conventions at: 

http://guides.rubyonrails.org/ 

11.4.1 Creating database objects 

The following examples use the orders and items tables from the stores7 

database. Due to the convention rules used on Rails, we must modify the 

schema of the tables to follow the Rails conventions. 

Example 11-25 shows the SQL script we use to change the name of the two 

tables, create views to incorporate the ID column, and create the SQL sequence 

required for object reference. 

Example 11-25 The setup.sql script 

-- Orders table 

RENAME TABLE orders TO order; 

CREATE VIEW orders( 

id, 

order_date, 

customer_num, 

ship_instruct, 

backlog, 

po_num, 

ship_date, 

ship_weigh, 


ship_charge, 

paid_date) AS 

SELECT * FROM order; 

CREATE SEQUENCE orders_seq; 

-- Items table 

RENAME TABLE items TO item; 

CREATE VIEW items ( 

id, 

order_num, 

stock_num, 

manu_code, 

quantity, 

total_price) AS 

SELECT * FROM item; 

CREATE SEQUENCE items_seq; 

11.4.2 Creating the Rails application 

You must create a Rails application using Rails commands before adding any 

objects or definitions. 

Example 11-26 shows the output of the rail stores command. 

Example 11-26 Output of the rail stores command 

C:\work>rails stores 

create 

create app/controllers 

create app/helpers 

create app/models 

create app/views/layouts 

create config/environments 

create components 

create db 

create doc 

create lib 

create lib/tasks 

create log 

create public/images 

create public/javascripts 

create public/stylesheets 

... 


For more information, refer to: 


11.4.3 Modifying the database configuration file 

The database.yml file must include the connection details of the database. 

Example 11-27 shows the database configuration file used by our application. 

Example 11-27 The database.yml file 

C:\work\stores>type config\database.yml 

development: 



pool: 5 

timeout: 5000 







test: 




password: 


production: 



pool: 5 

timeout: 5000 




C:\work\stores> 


11.4.4 Creating the Rails model and controllers 

To make Rails aware of the database tables, you create model and controller in 

your application. We use the model and controller Ruby script to create model 

and controller for the two tables used in our application. 

Example 11-28 shows the batch script used to generate the model and controller 

for the Items and Orders table. 

Example 11-28 The objects.cmd script 

ruby script\generate model Order 

ruby script\generate controller Order 

ruby script\generate model Item 

ruby script\generate controller Item 

Example 11-29 shows the output of each of the commands in the objects.cmd 

batch script. 

Example 11-29 Output of the objects.cmd script 

C:\work\stores>ruby script\generate model Order 

exists app/models/ 

exists test/unit/ 

exists test/fixtures/ 

create app/models/order.rb 

create test/unit/order_test.rb 

create test/fixtures/orders.yml 

exists db/migrate 

create db/migrate/004_create_orders.rb 

C:\work\stores>ruby script\generate controller Order 

exists app/controllers/ 

exists app/helpers/ 

create app/views/order 

exists test/functional/ 

create app/controllers/order_controller.rb 

create test/functional/order_controller_test.rb 

create app/helpers/order_helper.rb 

C:\work\stores>ruby script\generate model Item 




create app/models/item.rb 

create test/unit/item_test.rb 

create test/fixtures/items.yml 



exists db/migrate 

create db/migrate/005_create_items.rb 

C:\work\stores>ruby script\generate controller Item 



create app/views/item 


create app/controllers/item_controller.rb 

create test/functional/item_controller_test.rb 

create app/helpers/item_helper.rb 


After the objects are created, you must modify the controller Ruby file for each 

object to build the object scaffold. We use Rails 1.2.6 on our examples. Rails 2.x 

does not support dynamic scaffolding. This means it cannot retrieve the 

information for the table column dynamically. In this case, the scaffold for the 

objects must be created manually while creating the model object. We add the 

instruction scaffold: object_name to each of the files for creating scaffold. 

Example 11-30 shows the Ruby script file for the Item and Order controllers. 

Example 11-30 Controller script 

C:\work\stores>cat app/controllers/order_controller.rb 

class OrderController < ApplicationController 

scaffold :Order 

end 

C:\work\stores>cat app/controllers/item_controller.rb 

class ItemController < ApplicationController 

scaffold :Item 

end 


For more information about the changes in Rails 2.x, refer to: 

http://rubyonrails.org/documentation

11.4.5 Starting the Rails web server 

To start the Rails web server use the ruby script/server command. 

Example 11-31 demonstrates how to start the server. 

Example 11-31 Rails web server 

C:\work\stores>ruby script/server 

=> Booting WEBrick... 

=> Rails application started on http://0.0.0.0:3000 

=> Ctrl-C to shutdown server; call with --help for options 

[2010-07-05 10:40:00] INFO WEBrick 1.3.1 

[2010-07-05 10:40:00] INFO ruby 1.8.7 (2010-01-10) [i386-mingw32] 

[2010-07-05 10:40:00] INFO WEBrick::HTTPServer#start: pid=1092 port=3000 

11.4.6 Demonstrating website application 

At this point, Rails should have constructed the application for you, and you can 

browse and change the information for your table. 

We can open a web browser and navigate to the local web server to browse the 

the Order and Item tables: 

http://127.0.0.1:3000/item 

http://127.0.0.1:3000/order 


Figure 11-1 shows the Listing items page. The page contains links to perform all 

the typical operations that are associated with a database table (select, insert, 

update, and delete). 

Figure 11-1 Item listing web page 

Figure 11-2 shows the New Item page with all the fields from the Item table ready 

to be used to insert a new record into the table. 

Figure 11-2 Item New web page 


Figure 11-3 shows the Listing Orders page. 

Figure 11-3 List Order webpage 

The web applications development with Ruby on Rails was designed to be an 

effortless task. With just four commands and a little configuration, we created a 

website that can handle the common table operations for a database application. 

11.5 Using the Rails Adapter with IBM_DB 

In this section, we demonstrate how to create a basic web application using the 

Rails framework with the IBM_DB Adapter. The sample program is a simple 

telephone directory application for a user to list, add, update, and delete phone 

entries. 

Rails can be used to generate the Data Definition Language (DDL) for the 

database objects. We show how to create tables with Ruby on Rails. 


11.5.1 Creating the Rails application 

Use the rails command to create the Rails application. We create our 

application sample in the C:\RailsProjects directory. 

Example 11-32 shows how to create a rails application and the rails command 

output of our application. 

Example 11-32 Creating a Rails application 

C:\RailsProjects>rails sample 

create 

create app/controllers 

create app/helpers 

create app/models 

create app/views/layouts 

create config/environments 

create config/initializers 

... 

11.5.2 Modifying the database configuration file 

Update the database.yml database configuration file with the database 

connectivity details. 

Example 11-33 shows the configuration file for our development database. The 

name of the adapter, ibm_db, correspond to the Ruby Adapter for IBM Data 

Servers. 

Example 11-33 The database.yml file 

development: 

adapter: ibm_db 

database: ruby 


password: Ifmx4you 

host: kefka.lenexa.ibm.com 

port: 9089 

# Warning: The database defined as "test" will be erased and 

# re-generated from your development database when you run "rake". 


test: 

production: 


11.5.3 Creating model, control, and view 

Ruby on Rails worked on a Model, Control, View architecture. You can create 

model, control, and view components in stages. Here, we show a quick way of 

using the scaffold command to have Rails create the complete application, 

including all the directories and necessary files. 

The telephone table of our application use strings for first name, last name, and 

phone number. This table layout forms the model for our application. We specify 

this model right on the scaffold command as shown in Example 11-34. 

We invoke the command from the root directory of our project with the ruby 

script\generate script. The syntax for the scaffold options is: 

scaffold .. 

The output shows that Rails creates the necessary models, views and 

controllers. This command also generates the script to create the tables that are 

necessary to associate with the model. 

Example 11-34 Creating a scaffold 

C:\RailsProjects\sample>ruby script\generate scaffold phonedir 

first_name:string last_name:string phone:string 




create app/views/phonedirs 

exists app/views/layouts/ 



create test/unit/helpers/ 

exists public/stylesheets/ 

create app/views/phonedirs/index.html.erb 

... 

dependency model 




create app/models/phonedir.rb 

create test/unit/phonedir_test.rb 

create test/fixtures/phonedirs.yml 

create db/migrate 

create db/migrate/20100704234009_create_phonedirs.rb 


11.5.4 Migrating the model 

Ruby on Rails calls the creation of the database objects backing the model as 

migration. The scaffold command created a migrate script for creating the table 

attached to the model. 

Example 11-35 shows the db/migrate/20100704234009_create_phonedirs.rb 

migration file that is created by the scaffold command. This script has both 

create and drop sections, which means that you can roll back any migration. We 

created a model by the name phonedir. Ruby on Rails then created the table 

phonedirs, which is a plural form of the model name, which is the Ruby on Rails 

naming convention. 

Example 11-35 The phonedir migration file 

class CreatePhonedirs < ActiveRecord::Migration 

def self.up 

create_table :phonedirs do |t| 

t.string :first_name 

t.string :last_name 

t.string :phone 

t.timestamps 

end 

end 

def self.down 

drop_table :phonedirs 

end 

end 

Use the rake utility to migrate the file and create table in the database. The rake 

utility is a Ruby build script with capabilities similar to the make utility. You can use 

the rake utility to generate the database schema using a migration file. 

Example 11-36 shows how to run the rake script to create the model in the 

database. 

Example 11-36 Creating model 

C:\RailsProjects\sample>rake db:migrate 

(in C:/RailsProjects/sample) 

== CreatePhonedirs: migrating ================================================ 

-- create_table(:phonedirs) 

-> 0.0781s 

== CreatePhonedirs: migrated (0.0781s) ======================================= 


Example 11-37 uses the Informix dbschema utility to export the table schema to 

check the tables created Ruby on Rails migration. We started with an empty 

database and the output shows that two tables were created: 

► schema_migrations 

Ruby on Rails uses this table to keep track of the various version of the table, 

which allows you to roll back to the previous version. 

► phonedirs 

In this application table, Ruby added a few columns that we did not specify: 

– id: This serial column is for the primary key required by Ruby on Rails. 

– created_at and updated_at: Ruby on Rails uses these optionally. 

Example 11-37 The dbschema on database Ruby output 

% dbschema -d ruby 

DBSCHEMA Schema Utility INFORMIX-SQL Version 11.50.FC7 

grant dba to "informix"; 

... 

create table "informix".schema_migrations 

( 

version varchar(255) not null 

); 

... 

create table "informix".phonedirs 

( 

id serial not null , 

first_name varchar(255), 

last_name varchar(255), 

phone varchar(255), 

created_at datetime year to fraction(5), 

updated_at datetime year to fraction(5), 

primary key (id) 

); 

... 

create unique index "informix".unique_schema_migrations on "informix" 

.schema_migrations (version) using btree ; 


11.5.5 Starting the Rails web server 

Example 11-38 shows how to start the Rails WEBrick server from the root 

directory. The http port number is 3000. 

Example 11-38 Starting the WEBrick server 

C:\RailsProjects\sample>ruby script\server 

=> Booting WEBrick 

=> Rails 2.3.8 application starting on http://0.0.0.0:3000 

=> Call with -d to detach 

=> Ctrl-C to shutdown server 

[2010-07-04 17:25:22] INFO WEBrick 1.3.1 

[2010-07-04 17:25:22] INFO ruby 1.9.1 (2010-01-10) [i386-mingw32] 

[2010-07-04 17:25:22] INFO WEBrick::HTTPServer#start: pid=292 port=3000 

11.5.6 Checking the application from website 

You can start the web application using the local web server address: 

http://localhost:3000/phonedirs 

Figure 11-4 shows the initial screen that our application opened with 

http://localhost:3000/phonedirs. 

Figure 11-4 Initial screen of the application 


We add one phone entry to our directory as shown in Figure 11-5. 

Figure 11-5 Creating a new phone listing 

Figure 11-6 shows that a phone entry is added. 

Figure 11-6 Listing phonedir after the new entry 

For more information regarding the development with Ruby and Ruby on Rails, 

refer to: 




Chapter 12. Informix 4GL Web Services 

In this chapter, we introduce the new Web Services feature of IBM Informix 4GL. 

This chapter provides an overview and configuring and building Web Services 

using Informix 4GL. 

In this chapter, we discuss the following topics: 

► Basic concepts 


► Informix 4GL Web Services tools 

► Developing a web service with I4GL 

► Consuming a web service with I4GL 

► Troubleshooting 

12 


12.1 Basic concepts 

In this section, we provide an introduction of the products and technologies that 

we discuss in this chapter. 

12.1.1 IBM Informix 4GL 

Informix 4GL is a programming language developed by IBM for interacting with 

Informix database servers. It provides a rich environment for easy development 

of relational database applications. Informix 4GL provides all the component 

needed to develop character based applications using an Informix database, for 

example, project management, reports, debugger, and so on. 

Informix 4GL supports compilers that can convert the I4GL applications to C 

language or to generate platform-independent pseudo code that can be executed 

using a I4GL runner. 

For more information about Informix 4GL, refer to the 4GL Reference Manual at: 

http://publib.boulder.ibm.com/infocenter/ifxhelp/v0/index.jsp?topic=/com.ibm.to 

ols.doc/4gl.html 

12.1.2 Service-oriented architecture and Web Services 

Service-oriented architecture (SOA) is an architectural style that provides 

methods for systems development and integration, allowing applications 

developed with different technologies or programing languages to exchange data 

with one another. 

This exchange of data is accomplished through the use of Web Services. Web 

services are saleable functions that can be accessed independent of platforms 

and programming languages. These functions take a set of inputs and return a 

set of outputs to accomplish a specific task. 

Refer to the Service Oriented Architecture — SOA portal for more information: 

http://www.ibm.com/software/solutions/soa/ 

12.1.3 Web Services development 

You can create a web service with any web-aware technology. Java is the most 

common language that is used for Web Services development. However, you can 

create Web Services with other language and technologies, such as C or .NET 


IBM provides the following options for SOA development: 

► IBM SOA Sandbox 

► IBM Rational® Application Developer 

► eKit: Enterprise Architect for SOA 

You can develop a web service that requires the use of an IBM Informix database 

using the following languages: 

► Java, using any of the JDBC drivers for an Informix database 

► Any .NET language, using any of the Informix .NET providers available 

► IBM Informix 4GL 

12.1.4 Informix 4GL and Web Services 

12.1.5 Components 

Starting form version 7.50 of IBM Informix, 4GL developers can manage and 

create Web Services using the 4GL language. 

One of the key benefits of using Informix 4GL is the easy interaction with the 

Informix database server. The use of SQL statements to access database 

objects does not require any specific code as with other programming languages, 

because SQL is embedded in the I4GL language. 

The ability to create Web Services directly with I4GL allows the reuse of existing 

code. Existing solutions that are developed with I4GL can be converted to web 

solutions without much effort. 

With Informix 4GL, you can publish existing I4GL functions as Web Services and 

use existubg Web Services from any I4GL application. 

Informix 4GL uses the Axis2 web service wrapper API to implement the interface 

that is required to communicate between the web server and the Informix 4GL 

libraries. 

A typical I4GL web service solution includes the following components: 

► Apache AXIS2C server 

► Web service 

► Informix 4GL 

► Informix Database Server 

Chapter 12. Informix 4GL Web Services 401

A web service can perform the following operations: 

► Create is the process of creating the web service and publishing it to make it 

available to consumers. 

The term used in Informix 4GL for this task is Publish. 

► Consume is the process of using the web service, providing input parameters, 

and retrieving the result as output parameters for the function. 

The term used in Informix 4GL for this task is Subscribe. 

Axis2 C functions are used for both operations as the wrapper code between the 

web service and Informix 4GL. 


In this section, we discuss the setup and configuration needed to develop Web 

Services with Informix 4GL. 

12.2.1 Prerequisites and supported platforms 

The following prerequisites are required to use Web Services with Informix 4GL: 

► Apache Axis2/C version 1.5.1 (bundled with Informix 4GL) 

► Apache Axis2/Java version 1.3.1 (bundled with Informix 4GL) 

► IBM Informix database server version 10 or later 

► Java Runtime Environment (JRE) 1.5 or later 

► Perl 5.8.8 

IBM Informix 4GL 7.50 is supported in the following platforms: 

► HP-IA 11.23 and 11.31 

► AIX 5.3 and 6.1 

► Solaris 5.9 or 5.10 

► Red Hat Enterprise Linux 4 and 5 

► SUSE Linux Enterprise Server 10 

Note: The Web Services feature was added to Informix 4GL version 7.50.xC1 

but was available only for Linux platforms. Since version 7.50.xC3, all the 

platforms listed previously are supported. 


12.2.2 Environment 

The utilities for using Web Services with Informix 4GL are installed in the same 

directory as Informix 4GL. 

We do not discuss how to install and set up Informix 4GL in this book. For more 

information, refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.4gl_install 

.doc/fgl_ing_010.htm 

To use any of the I4GL Web Services tools, you must set the variables listed in 

Table 12-1 in the development environment. These variables define the location 

of those 4GL, Java, and Axis2 resources that you need for application 

development and deployment. 

Table 12-1 Environment variables 

Variable Description 

AXIS2C_HOME Specifies the Axis2 installation directory 

CLASSPATH Path to the required Java classes 

DBPATH Path for support files. Must be $INFORMIXDIR/etc 

INFORMIXDIR Directory where the 4GL files are installed 

INFORMIXSERVER Default database server 

INFORMIXSQLHOSTS Optional: Specifies the location of the sqlhosts 

file, which contains database connectivity 

information 

JAVA_HOME Must be set to point to JRE 1.5 or later 

Load Library Path 

for example: LD_LIBRARY_PATH 

Specifies which directories to search for client or 

shared IBM Informix general libraries 

PATH Specifies which directories to search for 

executable programs. Must include the following 

path: 

$INFORMIXDIR/bin and $JAVA_HOME/bin 

SOA_ERR_LOG Optional: Specifies the directory where the log file 

(w4glerr.log) is created, defaults to /tmp 

PROGRAM_DESIGN_DBS Optional: Database used for storing web service 

definitions, defaults to syspgm4gl 


Example 12-1 shows a typical shell script to set up these variables. 

Example 12-1 The setup.ksh script 

AXIS2C_HOME=$INFORMIXDIR/AXIS2C 

AXJDIR=$INFORMIXDIR/AXIS2C/AXIS2JARS 

CLASSPATH=$AXJDIR/wsdl4j-1.6.2.jar:$AXJDIR/backport-util-concurrent-2.2.jar:$AX 

JDIR/XmlSchema.jar:$AXJDIR/XmlSchema-1.3.1.jar:$AXJDIR/xbean-2.2.0.jar:$AXJDIR/ 

axiom-dom-1.3.1.jar:$AXJDIR/axiom-impl-1.3.1.jar:$AXJDIR/axiom-api-1.3.1.jar:$A 

XJDIR/neethi-1.3.1.jar:$AXJDIR/axis.jar:$AXJDIR/commons-logging.jar:$AXJDIR/wsd 

l2ws.jar:$AXJDIR/commons-discovery.jar:$AXJDIR/jaxrpc.jar:$AXJDIR/saaj.jar:$AXJ 

DIR/wsdl4j.jar:$AXJDIR/axis2-java2wsdl-1.3.1.jar:$AXJDIR/axis2-codegen-1.3.1.ja 

r:$AXJDIR/axis2-kernel-1.3.1.jar 

DBPATH=$INFORMIXDIR/etc 

LD_LIBRARY_PATH=$INFORMIXDIR/AXIS2C/lib:$LD_LIBRARY_PATH 

export AXIS2C_HOME AXJDIR CLASSPATH DBPATH LD_LIBRARY_PATH 

Some of the I4GL Web Services utilities, such as w4gl, keep design and 

configuration information in a database on the Informix database server. The 

default name for this database is syspgm4gl. The database is created the first 

time the w4gl tool is invoked. You can specify your own database name using the 

environment variable PROGRAM_DESIGN_DBS. 

12.3 Informix 4GL Web Services tools 

This section describes the tools that are available within Informix 4GL to publish, 

deploy, package, and subscribe Web Services. 

12.3.1 The w4glc Web Services compiler 

The w4glc Web Services compiler is a script based on Perl. The w4glc compiler 

performs all the required task to use Web Services within 4GL, from the creation 

process to deploying and packaging. 

The w4glc script is used by other I4GL utilities in a non-interactive way. Any error 

or failure that is generated during the execution of the script is written to the 

SOA_ERR_LOG log file. 

To execute the w4glc utility, use the following syntax: 

w4glc {-option} 

The w4glc utility does not keep any information in the database. It uses only 

configuration files. The configuration file is a text file that specifies the details 

about the I4GL function that is created as a web service. It contains information 


such as the location of the 4GL source files, input and output parameters, and 

database connectivity information. 

Table 12-2 lists the parameters that are available with the w4glc utility. 

Table 12-2 The w4glc utility parameter list 

Option Description 

check Reads the configuration file and performs basic checks, such 

as ensuring that the identified source files exist 

compile Compiles generated intermediate code 

deploy Deploys the web service on the AXIS2C server 

force Overwrites the existing service with identical name 

generate Generates the intermediate code for publish/subscribe 

help Provides basic help information 

keep Retains intermediate source files for troubleshooting 

package Bundles a web service for production deployment 

silent Generates code without on-screen display 

version Prints the version number 

Example 12-2 shows the output for the generate option. 

Example 12-2 The w4glc utility generate output 

informix@irk:/work$ w4glc -generate ./ws_zipcode_irk.4cf 

Begin environment check ... 

Environment check is completed. 

Generating code. Please wait ... 

Generating Wrapper code .... 

The wrapper file is /tmp/w4gl_informix/zipcode_details_wrap.c 

Generating WSDL .... 

Generating headers .... 

Generating skeletal code .... 

Code generation completed. 

Removing /tmp/w4gl_informix/zipcode_details_wrap.c ... 

Removing /tmp/w4gl_informix/zipcode_details.wsdl ... 

Removing /tmp/w4gl_informix/axis2_skel_ws_zipcode.h ... 

Removing /tmp/w4gl_informix/axis2_svc_skel_ws_zipcode.c ... 

Removing /tmp/w4gl_informix/services.xml ... 

Removing /tmp/w4gl_informix/axis2_skel_ws_zipcode.c ... 



12.3.2 The w4gl utility 

For additional information about the I4GL Web Services compiler, refer to: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.4gl_admin.d 

oc/fgl_wsg_500.htm 

The character-based interface w4gl utility is the main tool when using Web 

Services with Informix 4GL. It allows you to perform the same task as the 

command line tool, w4glc, but it also manages the data within the program 

design database, syspgm4gl. 

The design database contains the following information about the Web Services 

environment: 

► Information for the host system, such as the host name or temporary 

directories 

► Location for the Axis2 web server 

► Details for the Informix servers to which the Web Services connects 

► Definition for Web Services, such as function names or parameters types 

The web service definition that is specified through the utility is saved in 

database tables and is available for future reuse and modification, thus reducing 

development effort. 

The w4gl utility uses the same I4GL character-based interface as other 4GL tools 

to accomplish the creation and consumption of Web Services. 

Example 12-3 shows the main menu of the w4gl utility. 

Example 12-3 The w4gl utility main menu 

+------------------------------------------------------------------------------+ 

|W4GL: Publish Subscribe Host name App server Exit | 

|Create and Deploy web services from I4GL functions. | 

|--------------------------------[ irkpgm4gl ]-------------------[Help: CTRL-W]| 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 


| | 

| | 

| | 

| | 

| | 

| | 

+------------------------------------------------------------------------------+ 

The w4gl utility offers the following options: 

► Use the Publish option to create a new web service. 

► Use the Subscribe option to consume a web service. 

► Use the Host name option to managed the host information that is stored in 

the design database. 

► Use the Application server option to managed the Axis2 information that is 

stored in the design database. 

For a detailed description of all the w4gl utility menu options, refer to the 4GL 

Web Services Administration Guide, which is available at: 


4gl_admin.doc/fgl_wsg_006.htm 

12.3.3 Web Services Description Language Parser (wsdl_parser) 

Web Services Description Language (WSDL) is an XML-based language for 

describing network services. You can use WSDL to describe all the functions and 

parameters for a web service. 

When you subscribe a web service, the wsdl_parser tool parses the WSDL file to 

retrieve all the information that is required to define a web service. 

The syntax to invoke the wsdl_parser tool is: 

wsdl_parser sid wsdl_path ws_func i4gl_func target_dir target_file 

Table 12-3 describes each parameter. All of the parameters are required for the 

tool to work correctly. 

Table 12-3 The wsdl_parser tool parameters list 


sid An integer that uniquely identifies the subscriber 

wsdl_path Location of the file that describes the complete description of the 

web service; can be an online or a local copy of the WSDL file 



ws_func Function to consume within the designated web service 

i4gl_func Name for the wrapper function to be used by the I4GL program 

target_dir The path where files are stored while the web service is being 

consumed 

target_file The file name that contains the generated subscriber client code 

Note: The sid parameter is used only when you invoke the wsdl_parser from 

the w4gl tool. This parameter is ignored if you use wsdl_parser from the 

command line. 

Example 12-4 shows the wsdl_parser tool used to generate the configuration file 

for a ws_zipcode web service. This example passes the WSDL definition directly 

from a web server as the following wsdl_path parameter: 

http://irk:9876/axis/services/ws_zipcode?wsdl 

Example 12-4 The wsdl_parser tool output 

informix@irk:/work$ wsdl_parser 0 http://irk:9876/axis/services/ws_zipcode?wsdl 

zipcode_details zipcode4gl `pwd`/publish zipcode4gl.c 

informix@irk:/work$ ls publish 

local.wsdl zipcode4gl.c_zipcode4gl.4cf 



12.3.4 I4GL Web Services process 

Figure 12-1 illustrates how the I4GL Web Services tools work together. 

Figure 12-1 I4GL Web Services tools 

12.4 Developing a web service with I4GL 

In this section, we demonstrate the steps that are required to create a web 

service using IBM Informix 4GL. Publish and subscribe are two operations to 

perform with a web service: 

► Publish 

The tasks required to create a new web service with the w4gl utility are: 

a. Add the Host name and an Axis2 server information. 

b. Add the web service definition details. 

c. Generate the web service configuration file for publishing. 

d. Deploy a web service by registering the service in the Axis2 web server. 

e. Package a web service as a single file (a .tar file) that is ready for the 

production server. 

► Subscribe 

The tasks needed to consume a web service are with the w4gl tool are: 

a. Add details for the web service to consume. 

b. Compile the Web Services wrapper code that generates the configuration 

file for subscription. 


In the remaining sections, we describe how to publish a simple I4GL function as 

a web service and show that the function can be used from other languages such 

as Java. 

12.4.1 Example I4GL function 

We use a basic I4GL function, state_name(), for the web service. This function 

connects to the database server and retrieves the name for a specific state code. 

Example 12-5 shows the 4GL code state_name() saved in the state_name.4gl 

file. This function queries the state table from the stores_demo database. The 

state_name() function takes one input parameter state code of type CHAR(2) 

and returns the state name that has CHAR(15) data type. 

Example 12-5 The state_name.4gl file 

FUNCTION state_name(code) 

DEFINE state_rec RECORD 

code CHAR(2), 

sname CHAR(15) 

END RECORD, 

code CHAR(2), 

sel_stmt CHAR(100); 

LET sel_stmt= "SELECT code, sname FROM state WHERE code = ?"; 

PREPARE st_id FROM sel_stmt; 

DECLARE cur_id CURSOR FOR st_id; 

OPEN cur_id USING code; 

FETCH cur_id INTO state_rec.*; 

CLOSE cur_id; 

FREE cur_id; 

FREE st_id; 

RETURN state_rec.sname 

END FUNCTION 

To ensure that the 4GL code is correct, we compile the function with the I4GL 

compiler, c4gl, as shown in Example 12-6. 

Example 12-6 Compile 4GL function 

informix@irk:/work$ c4gl -c state_name.4gl 



12.4.2 Host and application details 

Before adding any of the details for the web service, we must provide details 

about the system where the web service will run and the Axis2 server that is 

used. To complete these tasks, we use the “Host name” and “Application server” 

menus from the w4gl utility. 

Example 12-7 shows the HOST INFORMATION form with the host name irk and 

the /tmp/w4gl_informix temporary directory. 

Example 12-7 Host name menu 

+------------------------------------------------------------------------------+ 

|HOST NAME: Query Next Previous Add Modify Remove Exit | 

|See the existing host name details. | 

|[1 of 1]------------------------[ irkpgm4gl ]-------------------[Help: CTRL-W]| 

| | 

| HOST INFORMATION | 

| | 

| Machine ID [ 1] | 

| Host Name [irk ] | 

| Temporary Directory [/tmp/w4gl_informix ] | 

| [ ] | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

+------------------------------------------------------------------------------+ 

Host information includes the following fields: 

► Machine ID is an automatic identifier number. 

► Host Name is the system name where the Axis2 server is installed. 

► Temporary Directory is the directory that is used by the w4glc utility for 

creating temporary files. 

After you define the host information, add the information for the Axis2 

application server using the APP SERVER menu. 


Example 12-8 shows the APP SERVER form. 

Example 12-8 Application menu 

+------------------------------------------------------------------------------+ 

|APP SERVER: Query Next Previous Add Modify Remove Exit | 

|Go to the next app server | 


| | 

| APP SERVER INFORMATION | 

| Server ID [ 1] | 

| Server Name [axis ] | 


| Port Number [ 9876] | 

| ENVIRONMENT VARIABLES | 

| INFORMIXDIR [/usr3/4gl750 ] | 

| INFORMIXSQLHOSTS [/usr3/sqlhosts ] | 

| CLIENT_LOCALE [en_us.utf8 ] | 

| DBDATE [Y4MD- ] | 

| Notes [ ] | 

| [ ] | 

| [ ] | 

| [ ] | 

| | 

| | 

| | 

+------------------------------------------------------------------------------+ 

An application server is identified by the following fields: 

► Server ID is an automatic identifier number. 

► Server Name is the name of the Axis2 server. 

► Host Name is the system name where the Axis2 server runs. 

► Port Number is the port used for incoming connections to the web service. 

The APP SERVER option is also used to stored specific environment information 

for the application server. This information is required because the Axis2 server 

binary loads the I4GL libraries that might need additional resource files located in 

the $INFORMIXDIR directory. 

12.4.3 Definition of the web service 

In this section, we demonstrate how to define a web service from the w4gl utility. 

To define a web service: 

1. Add the IBM Informix database that the web service will use. 

2. Add the definition for the web service, such as the name of the service or the 

name of the 4GL function. 


3. Add specific details for the web service such as input and output variables. 

4. Add the location of the 4GL source code file. 

Add Informix database details 

You add Informix database details using the Database menu from the w4gl utility. 

Example 12-9 shows the DATABASE INFORMATION form with details of the 

database that we used in our example. 

Example 12-9 Database option 

+------------------------------------------------------------------------------+ 

|DATABASE: Query Next Previous Add Modify Remove Exit | 

|Go to the previous database record. | 


| | 

| DATABASE INFORMATION | 

| | 

| Database ID [ 1] | 

| Database Name [stores7 ] | 

| Database Server [irk1150 ] | 

| IDS Version [11.50 ] | 

| DB_LOCALE [en_US.819 ] | 

| Notes [ ] | 

| [ ] | 

| [ ] | 

| [ ] | 

| | 

| | 

| | 

| | 

| | 

| | 

+------------------------------------------------------------------------------+ 

This menu option uses the following fields: 

► Database ID is an automatic number that identifies a database definition. 

► Database name defines the database name to which the web server connects. 

► IDS Version is the Informix database server version number. 

► DB_LOCALE is the locale of the database. The default DB_LOCALE is en_US.819. 


Add details about the web service 

You can add details about the web service using the Add option in the web 

service menu. Example 12-10 shows this option. 

Example 12-10 Add the web service menu 

+------------------------------------------------------------------------------+ 

|WEB SERVICE: Query Next Previous Add Modify Remove Install ... | 

|Specify a new service record. | 


| | 

| | 

| | 

First, you add the web service name and the function name using the Detail 

menu option. Example 12-11 shows this input form with the details of our web 

service. 

Example 12-11 Web service details 

+------------------------------------------------------------------------------+ 

|ADD: Detail Variable File Exit | 

|Specify the web service parameters. | 


| | 

| Webservice ID [ 4] | 

| Webservice Name [ws_statename ] | 

| Function Name [state_name ] | 

| Notes [Returns the state name for a given code ] | 

| [ ] | 

| [ ] | 

| [ ] | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

+------------------------------------------------------------------------------+ 

The following input details on this form describes a web service: 

► Webservice ID is an automatically generated identifier for the web service. 

► Webservice Name is the name of the web service. 

► Function Name is the he name of the 4GL function. 


Input and output variables 

Next, you add the input and output variables that the web service uses with the 

Variable menu option. Example 12-12 shows this menu option. Our function 

takes an CHAR(2) input parameter and returns a CHAR(15) value. 

Example 12-12 Web service VARIABLE option 

+------------------------------------------------------------------------------+ 

|VARIABLE: Input Output Exit | 

|Exit the Variable menu. | 


| | 

| [ 1] Input parameter - Variable name Data type | 

| | 

| [ 1][code ][CHAR(2) ] | 

| [ ][ ][ ] | 

| [ ][ ][ ] | 

| [ ][ ][ ] | 

| [ ][ ][ ] | 

| | 

| [ 1] Output parameter - Variable name Data type | 

| | 

| [ 1][sname ][CHAR(15) ] | 

| [ ][ ][ ] | 

| [ ][ ][ ] | 

| [ ][ ][ ] | 

| [ ][ ][ ] | 

| | 

| | 

+------------------------------------------------------------------------------+ 


Source file information 

Finally, you define a web service. We stored the location of the I4GL source file 

that contains our function using the File menu option. Example 12-13 shows the 

fields used by the File option. 

Example 12-13 Web service File option 

+------------------------------------------------------------------------------+ 

|ADD: Detail Variable File Exit | 

|Exit the web services Add menu. | 


| | 

| Service Name [ws_state_name ] | 

| Function Name [state_name ] | 

| | 

| File Number [ 1] | 

| Directory [/work ] | 

| File Name [state_name.4gl ] | 

| | 

| File Number [ ] | 

| Directory [ ] | 

| File Name [ ] | 

| | 

| File Number [ ] | 

| Directory [ ] | 

| File Name [ ] | 

| | 

| | 

| | 

+------------------------------------------------------------------------------+ 

An I4GL function can require more than one I4Gl file. You must supply all the 

required file names and their directories. We supplied the 4GL file 

state_name.4gl that contains the state_name() function. 

12.4.4 Generate the configuration file 

With the details of the web service stored in the design database, you can then 

generate the configuration file (.4cf) for a Publish operation. The Generate 

option is inside the Install menu option. 


Example 12-14 shows the Generate form. You must complete every field in the 

form. If you stored the definition for these items in the design database, you can 

retrieve them using the Ctrl+B key shortcut. 

Example 12-14 Generate form 

+------------------------------------------------------------------------------+ 

|INSTALL: Generate Deploy Package Exit | 

|Generate the configuration file for a web service. | 


| | 

| +-----------------------------------------------------+ | 

| |DATABASES: Query Previous query Exit | | 

| Service ID [ 4] M|Make a new selection | | 

| |-----------------------------------------------------| | 

| Service Name [ws_s| DATABASE INFORMATION | | 

| Host Name [irk | | | 

| Temp Directory [/tmp|ID Database Name | | 

| [ |[ 1] [stores7 ]| | 

| App-Server Name [axis|[ ] [ ]| | 

| Port Number [ 98|[ ] [ ]| | 

| Database Name [ |[ ] [ ]| | 

| Database Server [ |[ ] [ ]| | 

| |[ ] [ ]| | 

| | | | 

| |Arrow key - Press Esc to Accept or press Ctrl+C to Ca| | 

| +-----------------------------------------------------+ | 

| | 

+------------------------------------------------------------------------------+ 

After you enter all the information, use the Generate option to create the 

configuration file. Example 12-15 shows the output of the Generate option. 

Example 12-15 Generate option 

+------------------------------------------------------------------------------+ 


|Generate the configuration file for a web service. | 


| | 

| GENERATE CONFIGURATION | 

| | 

| Service ID [ 4] Machine ID [ 1] Server ID [ 1] Database ID [ 1] | 

| | 

| Service Name [ws_state_name ] | 


| Temp Directory [/tmp/w4gl_informix ] | 

| [ ] | 

| App-Server Name [axis ] | 

| Port Number [ 9876] | 

| Database Name [stores7 ] | 

| Database Server [irk1150 ] | 

| | 

| Generated configuration file ws_state_name_irk.4cf | 

+------------------------------------------------------------------------------+ 


The Generate operation creates the configuration file that is required for 

publishing a web service. The name of the file is constructed using the web 

service name, the host name, and a .4cf extension. In our example, the name of 

the file is ws_state_name_irk.4cf. 

Example 12-16 shows the configuration file for the ws_state_name web service. 

Example 12-16 The ws_state_name_irk.4cf file 

[SERVICE] 

TYPE = publisher 

INFORMIXDIR = /usr3/4gl750uc3 

DATABASE = stores7 

CLIENT_LOCALE = en_us.utf8 

DB_LOCALE = en_US.819 

INFORMIXSERVER = irk1150 

HOSTNAME = irk 

PORTNO = 9876 

I4GLVERSION = 7.50.xC3 

WSHOME = /usr3/4gl750uc3/AXIS2C 

WSVERSION = axis 

TMPDIR = /tmp/w4gl_informix 

SERVICENAME = ws_state_name 

[FUNCTION] 

NAME = state_name 

[INPUT] 

[VARIABLE] NAME = code TYPE = CHAR(2) [END-VARIABLE] 

[END-INPUT] 

[OUTPUT] 

[VARIABLE] NAME = sname TYPE = CHAR(15) [END-VARIABLE] 

[END-OUTPUT] 

[END-FUNCTION] 

[DIRECTORY] 

NAME = /work 

FILE = state_name.4gl, 

[END-DIRECTORY] 

[END-SERVICE] 

You can use a configuration file (4cf) with the w4glc utility to perform tasks, such 

as generate and compile, directly from the command line. Example 12-17 shows 

how to perform all the steps that the w4gl deploy options performs using the 

w4glc utility. 

Example 12-17 Using w4glc 

informix@irk:/work$ w4glc -generate -compile -deploy ws_state_name_irk.4cf 






The wrapper file is /tmp/w4gl_informix/state_name_wrap.c 





Generating shared object for service ws_state_name .... 

Compiling code. Please wait... 

Executing: c4gl --shared -o /tmp/w4gl_informix/libws_state_name.so 

-I/usr3/4gl750/AXIS2C/include/axis2-1.5.0 -L/usr3/4gl750/AXIS2C/lib 

-laxis2_engine -laxutil -laxis2_axiom /tmp/w4gl_informix/state_name_wrap.c 

/tmp/w4gl_informix/axis2_skel_ws_state_name.c 

/tmp/w4gl_informix/axis2_svc_skel_ws_state_name.c /work/state_name.4gl 

/usr3/4gl750/lib/tools/w4glutil.a /usr3/4gl750/lib/tools/lib4gl.a 

Compilation done. 

Deploying service ws_state_name ... 

Deploying the service. Please wait ... 

Copying /tmp/w4gl_informix/libws_state_name.so ... 

Copying /tmp/w4gl_informix/services.xml ... 

Copying /tmp/w4gl_informix/state_name.wsdl ... 

Service name: ws_state_name 






Generating shared object for service ws_state_name .... 


Executing: c4gl --shared -o /tmp/w4gl_informix/libws_state_name.so 


-laxis2_engine -laxutil -laxis2_axiom /tmp/w4gl_informix/state_name_wrap.c 

/tmp/w4gl_informix/axis2_skel_ws_state_name.c 

/tmp/w4gl_informix/axis2_svc_skel_ws_state_name.c /work/state_name.4gl 

/usr3/4gl750/lib/tools/w4glutil.a /usr3/4gl750/lib/tools/lib4gl.a 

Compilation done. 

Deploying service ws_state_name ... 

Deploying the service. Please wait ... 

Copying /tmp/w4gl_informix/libws_state_name.so ... 

Copying /tmp/w4gl_informix/services.xml ... 

Copying /tmp/w4gl_informix/state_name.wsdl ... 

Service name: ws_state_name 

Deployed at : /usr3/4gl750/AXIS2C/services/ws_state_name 

Removing /tmp/w4gl_informix/state_name_wrap.c ... 

Removing /tmp/w4gl_informix/state_name.wsdl ... 

Removing /tmp/w4gl_informix/axis2_skel_ws_state_name.h ... 

Removing /tmp/w4gl_informix/axis2_svc_skel_ws_state_name.c ... 

Removing /tmp/w4gl_informix/services.xml ... 

Removing /tmp/w4gl_informix/axis2_skel_ws_state_name.c ... 

Removing /tmp/w4gl_informix/libws_state_name.so ... 

The output of the command line tool shows all the steps completed while creating 

and compiling the wrapper function. When errors occur during the deployment 


process, running each individual step with the w4glc utility might help to diagnose 

the reason for the problem. 

12.4.5 Deployment of the web service 

This process generates the auxiliary code that is required to link the Axis2 

application server with the I4GL function. During deployment, the C code for the 

web service is created and compiled automatically using the 4GL libraries. The 

result of this process is a shared library ready that can be used in the application 

server. 

This process also creates a WSDL file for the web service and copies this file, 

together with the web service shared library, into the application server directory. 

The Deploy option is part of the Install menu. Example 12-18 shows the 

deployment of the ws_state_name web service. 

Example 12-18 Deploy form 

+------------------------------------------------------------------------------+ 


|Deploy the web service. | 


| | 

| CONFIGURATION TO DEPLOY | 

| | 

| File Name [ws_state_name_irk.4cf ] | 

| [ ] | 

| [ ] | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| Deployed ws_state_name. | 

+------------------------------------------------------------------------------+ 


After a successful deployment, the web service is ready to be consume by any 

application. The files are copied into the Axis2 services directory automatically. 

Example 12-19 shows the web service files on the application server. 

Example 12-19 Application Server services directory 

informix@irk:/work$ ls $INFORMIXDIR/AX*/services/ws_state_name 

libws_state_name.so services.xml state_name.wsdl 


12.4.6 Packaging of the web service 

Packaging a web service is the process of creating a compressed file with all the 

components that are required by the web service. You can use the compressed 

file, in .tar format, on other Axis2 servers. Example 12-20 shows the Package 

menu option. 

Example 12-20 Package option 

+------------------------------------------------------------------------------+ 


|Package the web service. | 


| | 

| SERVICE PACKAGING | 

| | 

| File Name [ws_state_name_irk.4cf ] | 

| [ ] | 

| [ ] | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

| Packaging successful. Check $TMPDIR directory (in config file) for .tar file | 

+------------------------------------------------------------------------------+ 


The compressed file is left in the $TMPDIR directory. Example 12-21 shows the 

contents of the packaged file for the ws_state_name web service. 

Example 12-21 Packaged .tar file 

informix@irk:/work$ tar tvf /tmp/w4gl_informix/ws_state_name.tar 

drwxr-xr-x informix/informix 2010-07-05 21:01 ws_state_name/ 

-rw-r--r-- informix/informix 2010-07-05 21:01 ws_state_name/services.xml 

-rw-r--r-- informix/informix 2010-07-05 21:01 ws_state_name/state_name.wsdl 

-rwxr-xr-x informix/informix 2010-07-05 21:01 ws_state_name/libws_state_name.so 


12.4.7 Starting the Axis2 application server 

An Axis2 application server is included with the Informix 4GL package. It is 

located in the AXIS2C directory under the $INFORMIXDIR directory. 

The Axis2 application server must be started to consume a web service. It is not 

required during the development or deploy process. 

Example 12-22 demonstrates how to start the Axis2 application server. 

Example 12-22 Starting Axis2 

informix@irk:/usr3/4gl750/AXIS2C/bin$ ./axis2_http_server -p 9876 

Started Simple Axis2 HTTP Server ... 

For more information about the Axis2 application server, refer to: 

http://ws.apache.org/axis2/c/docs/axis2c_manual.html 

12.4.8 Consuming the I4GL web service 

The main feature of a web service is that it can be used by any application in any 

platform. A web service is not tied to the technology or programming language 

that is used to develop the service. Any application that supports SOAP can 

make use of the functions that are implemented inside a web service. SOAP is a 

simple XML-based protocol that is used to exchange information over an HTTP 

link. 

In this section, we demonstrate how to use the ws_state_name web service using 

a basic Java application. 


Getting a list of available Web Services 

You can get a list of available Web Services in the Axis2 application server by 

opening a web browser and connecting to the Axis2 server: 

http://hostname:port/axis/services 

Figure 12-2 shows the Web Services that are available in our example. 

Figure 12-2 Axis2 Web Services 

You can use the ?wsdl keyword to retrieve the WSDL file as follows: 

http://hostname:port/axis/services/ws_state_name?wsdl 


Figure 12-3 shows the WSDL information for the ws_state_name service. 

Figure 12-3 WSDL information for the ws_state_name service 

Java application 

The main advantages of Web Services is that the application that uses the 

services does not need to know anything about how the service is implemented. 

The information needed for consuming a web service is defined in the WSDL file, 

such as the name of the operations that it supports and the parameters that it 

requires. 

Example 12-23 demonstrates how to use the ws_state_name I4GL web service 

from a simple Java application. 

Example 12-23 The state_name.java file 

informix@irk:/work$ cat state_name.java 

import org.apache.axis.client.Call; 

import org.apache.axis.client.Service; 

import javax.xml.namespace.QName; 

public class state_name { 

public static void main(String [] args) { 

try { 

String endpoint = "http://irk:9876/axis/services/ws_state_name"; 

String qname = "http://www.ibm.com/ws_state_name"; 


Service service = new Service(); 

Call call = (Call) service.createCall();

} 

call.setTargetEndpointAddress( new java.net.URL(endpoint) ); 

call.setOperationName(new QName(qname, "state_name")); 

String ret = (String) call.invoke( new Object[] { args[0] } ); 

System.out.println("Sent 'CA', got '" + ret + "'"); 

} catch (Exception e) { 

System.err.println(e.toString()); 

} 

} 

informix@irk:/work$ javac state_name.java 

informix@irk:/work$ java state_name CA 

Sent 'CA', got 'California ' 

informix@irk:/work$ java state_name AR 

Sent 'CA', got 'Arkansas ' 


12.5 Consuming a web service with I4GL 

In this section, we demonstrate how to consume a web service using IBM 

Informix 4GL. 

12.5.1 Web service to consume 

You can use the w4gl utility to insert details about the specific web service that 

you want to consume. The Subscribe menu option allows you to manage 

definitions for Web Services in the design database. 

Example 12-24 shows the Subscribe form with the details referring to the 

ws_state_name web service. 

Example 12-24 Subscribe form 

+------------------------------------------------------------------------------+ 

|SUBSCRIBE: Query Next Previous Add Modify Remove Compile Exit | 

|Specify a new web service definition. | 


| | 

| Subscription ID [ 3] | 

| WSDL Path [http://irk:9876/axis/services/ws_state_name?wsdl ] | 

| [ ] | 

| Webservice Function[state_name ] | 

| I4GL Function [statename ] | 


| Target Directory [/work/publish ] | 

| Target File Name [statename ] | 

| Notes [Wrapper for ws_state_name Web Service ] | 

| [ ] | 

| [ ] | 

| | 

| | 

| | 

| | 

| | 

| | 

| | 

+------------------------------------------------------------------------------+ 

This form includes the following details: 

► Subscription ID is an automatic generated identifier of the web service. 

► WSDL Path is the complete path of the WSDL file for the service. This path can 

be a local file or a URL. 

► Web service Function is the function name that is provided by the web 

service. 

► I4GL Function is the name of the wrapper C function. This name is the 

function that our I4GL used to invoke the web service operation. 

► Target Directory is the directory where the wrapper and configuration files 

are created. 

► Target File Name is the name of the C source file with the I4GL function. 

The configuration file for a publish operation is generated automatically by the 

w4gl utility, but you can also create it using the wsdl_parser as shown in 

Example 12-25. 

Example 12-25 Generating the configuration file 

informix@irk:/work$ wsdl_parser 0 

http://irk:9876/axis/services/ws_state_name?wsdl state_name wsstatecode 

`pwd`/publish statecode.c 

informix@irk:/work$ ls publish 

local.wsdl statecode.c_wsstatecode.4cf 

informix@irk:/work$ cat publish/statecode.c_wsstatecode.4cf 

[SERVICE] 

TYPE = subscriber 

I4GLVERSION = 7.50.xC4 

WSHOME = 0 

TARGET_DIR = /work/publish 

I4GL_FUNCTION = wsstatecode 

TARGET_FILE = statecode.c 

[WSDL_INFO] 


WSDL_PATH = /work/publish/local.wsdl 

WSDL_NAME_SPACE = http://www.ibm.com/state_name 

[FUNCTION] 

SERVICENAME = ws_state_name 

NAME = state_name 

[INPUT] 

[VARIABLE] NAME = code TYPE = char(2) [END-VARIABLE] 

[END-INPUT] 

[OUTPUT] 

[VARIABLE] NAME = sname TYPE = char(15) [END-VARIABLE] 

[END-OUTPUT] 

[END-FUNCTION] 

[END-WSDL_INFO] 

[END-SERVICE] 

12.5.2 Compiling the wrapper code 

Next, you need to generate and compile the wrapper code using the Compile 

menu option of the w4gl utility. Example 12-26 shows the w4gl utility after the 

wrapper code is compiled for the ws_state_name web service. 

Example 12-26 Compile option 

+------------------------------------------------------------------------------+ 

|SUBSCRIBE: Query Next Previous Add Modify Remove Compile Exit | 

|Compile the subscriber client code. | 


| | 

| Subscription ID [ 3] | 

| WSDL Path [http://irk:9876/axis/services/ws_state_name?wsdl ] | 

| [ ] | 

| Webservice Function[state_name ] | 

| I4GL Function [statename ] | 

| Target Directory [/work/publish ] | 

| Target File Name [statename ] | 

| Notes [Wrapper for ws_state_name Web Service ] | 

| +---------------------------------------------------------------------------+| 

| | || 

| |Subscriber code has been compiled successfully. || 

| +---------------------------------------------------------------------------+| 

| | 

| | 

| | 

| | 

| | 

+------------------------------------------------------------------------------+ 


After this process is complete, the C files for the wrapper function, including the 

object file that contains the function code, are left in the Target Directory that is 

specified in the web service definition. 

Example 12-27 shows the files for the ws_state_name web service. You can use 

these files from an Informix 4GL program to consume the web service. 

Example 12-27 Web service files 

informix@irk:/work/publish$ ls 

axis2_stub_ws_state_name_statename.h statename.c_statename.4cf 

statename.c statename.o 

informix@irk:/work/publish$ 

12.5.3 Using the web service from an I4GL application 

To consume a web service from I4GL, you have to link the object file for the 

wrapper function in the 4GL code or use the C source file that is generated 

during the subscribe compile process. 

Example 12-28 shows a simple 4GL program that uses the wrapper function for 

the ws_state_name web service. The wrapper function can be called like any 

other C function in I4GL. 

Example 12-28 The I4GL subscriber code: wsstate.4gl 

informix@irk:/work/publish$ cat wsstate.4gl 

MAIN 

DEFINE sname CHAR(15) 

WHENEVER ERROR STOP 

CALL statename("CA") RETURNING sname 

DISPLAY "State name: ",sname 

END MAIN 

informix@irk:/work/publish$ c4gl wsstate.4gl statename.c -o wsstate 

$INFORMIXDIR/lib/tools/w4glutil.a -I$AXIS2C_HOME/include/axis2-1.5.0 

-L$AXIS2C_HOME/lib -laxis2_engine 

informix@irk:/work/publish$ ./wsstate 

State name: California 

informix@irk:/work/publish$ 

For more information about Informix 4GL, refer to the 4GL Reference Manual at: 

http://publib.boulder.ibm.com/infocenter/ifxhelp/v0/index.jsp?topic=/com.ibm.to 

ols.doc/4gl.html 


12.6 Troubleshooting 

In this section, we discuss typical problems that can occur when developing a 

web service using the Informix 4GL Web Services tools and how to obtain 

diagnostic information through the use of tracing or log files. 

12.6.1 Typical problems 

This section lists typical problems that can occur. 

Connection 

Connection errors normally occur when there is something wrong in the 

configuration details for the development environment or the web service. 

Any web service developed in I4GL requires the use of the Informix 4GL 

communication libraries for the database connection. I4GL tools such as w4gl 

keep details about the environment in the Design database. Therefore, it is 

critical that the communication with the IBM Informix database was configured 

correctly before beginning any project. 

Environment variables such as INFORMIXDIR and INFORMIXSQLHOSTS must 

contain valid details for the Informix database server to use during development. 

Also, consider the following problems that are related to connection: 

► Confirm Informix database server details. Informix Web Services tools and 

Web Services running on the Axis2 server use the database information that 

is defined in the Design database. 

► Verify connection information. Connection information regarding the Axis2 

server, such as the host name or port number, is stored as part of an 

Application Server definition. Check that these values are valid. 

► Consuming Web Services with a 4GL application requires a TCP connection 

from the I4GL program to the application server that is running the web 

service. Make sure that the location of the web service is correct and that the 

application server can be reached from the I4GL process. 

Compilation errors 

A common reason for having compilation errors is due to an incorrect setup or 

incorrect use of the Informix 4GL Web Services utilities. 

Environment variables such as PATH and LD_LIBRARY_PATH (or the suitable 

variable for the platform) might cause compilation and runtime errors when 

developing a web service with Informix 4GL. When a compile problem occurs 


while using one of the I4GL web service tools, the information about the error is 

written into the W4GL log file. The default name and location of this file is 

/tmp/w4glerr.log. 

Example 12-29 shows an error message that is generated by the w4gl utility 

during the deploy process. 

Example 12-29 A w4gl error. 

The file "state_name.err" has been written. 

-CDCAK0012: The web service not deployed. Check error log '/tmp/w4glerr.log' 

The Deploy menu option performs several operations automatically, including 

generating the wrapper code, compiling, and moving the Web Services files into 

the Axis2 server. To know the specific task that is failing, use the web compiler 

utility (w4glc) to perform each individual task manually. 

By default, the w4glc script deletes the temporary files that are used to perform a 

task. Use the -keep flag to avoid file deletion. 

Example 12-30 shows how to run the generate process using the w4glc utility. 

Example 12-30 Using w4glc generate to avoid file deletion 

informix@irk:/work$ w4glc -generate -keep ws_state_name_irk.4cf 










With the wrapper files in the temporary directory, you can execute the compile 

process from the command line using the w4glc utility and examine the output for 

any errors. Example 12-31 shows the output of the compile process when an 

compilation error occurs. 

Example 12-31 Compilation output 

informix@irk:/work$ w4glc -compile -keep ws_state_name_irk.4cf 



Generating shared object for service ws_state_name ... 



Executing: c4gl -keep --shared -o /tmp/w4gl_informix/libws_state_name.so 


-laxis2_engine -laxutil -laxis2_axiom... 

The compilation was not successful. Errors found: 1. 

The file "state_name.err" has been written. 

Error executing: c4gl -keep --shared -o /tmp/w4gl_informix/libws_state_name.so 

-I/usr3/4gl750/AXIS2C/include/axis2-1.5.0 ... 

/usr3/4gl750/lib/tools/w4glutil.a /usr3/4gl750/lib/tools/lib4gl.a at 

/usr3/4gl750/lib/globals.pm line 583. 

Error executing: c4gl -keep --shared -o /tmp/w4gl_informix/libws_state_name.so 


-laxis2_engine -laxutil ... 


Similar to any I4GL program, if the error was inside the Informix 4GL code, a .err 

file is created that contains the error message. Example 12-32 shows the content 

of the state_name.err file. 

Example 12-32 The state_name.err file 

informix@irk:/work$ cat state_name.err 

FUNCTION state_name(code) 

DEFINE state_rec RECORD 

code CHAR(2), 

sname CHAR(15) 

END RECORD, 

code CHAR(2), 

sel_stmt CHAR(100); 

LET sel_stmt= "SELECT code, sname FROM state WHERE code = ?"; 

PEPARE st_id FROM sel_stmt; 

|________^ 

| 

| A grammatical error has been found on line 11, character 10. 

| The construct is not understandable in its context. 

| See error number -4373. 

DECLARE cur_id CURSOR FOR st_id; 

OPEN cur_id USING code; 

FETCH cur_id INTO state_rec.*; 

... 


Keeping the wrapper C files in the temporary directory might be useful when the 

compilation error appears inside the Axis2 functions. Example 12-33 shows the 

temporary files that are created with the generate option for the ws_state_name 

web service. 

Example 12-33 Temporary files 

informix@irk:/work$ ls /tmp/w4gl_informix/ 

axis2_skel_ws_state_name.c services.xml tmpXMLReqFile 

axis2_skel_ws_state_name.h state_name_wrap.c ws_state_name.tar 

axis2_svc_skel_ws_state_name.c state_name.wsdl 


While compiling any web service, during creation or consume, make sure all the 

required libraries and include files are passed to the compiler correctly. These 

requirements can vary from platform to platform. Always check the release notes. 

The release and documentation files for Informix 4GL are located in the 

release/en_us/0333 directory inside the INFORMIXDIR variable. These files 

contain additional information that is relevant to the version of I4GL that is 

installed, such as known issues or compiler requirements, that might help 

diagnose the problem. 

Consuming the web service 

Errors when consuming the web service might be caused by an invalid web 

service definition. Items such as the function name or parameters type are 

defined in the configuration file and are used to create the WSDL file that the 

application server uses to define the web service. You can retrieve the WSDL 

information for a web service using the location of the service and the ?wsdl 

suffix from any web browser. 


Figure 12-4 shows the WSDL information for the ws_state_name web service. 

Figure 12-4 WSDL for ws_state_name service 

Make sure the operations, parameters, and data types are correct for the I4GL 

code that the function uses. 

Testing a web service 

Informix I4GL does not provide any specific tool for testing Web Services. 

Although you can create a simple 4GL code to consume the web service, 

depending on the complexity of the web service, it can be more useful to perform 

a complete testing. 

You can use open source tools, such as soapUI, to test your web service before 

publish it in the production environment. For more information about soapUI, 

refer to: 

http://www.soapui.org/ 


12.6.2 Tracing 

A developer can use one of the following types of tracing when diagnosing an 

Informix 4GL web service problem: 

► Application server trace can be used to diagnose problems between a client 

application and the Axis2 application server. 

► Database trace can be used when diagnostic problems are specific to 

operations with the database server, such as SQL errors or incorrect data 

returned. 

Application server trace 

The Axis2c application server provides a method to trace all the exchanged 

messages between the application server and a client that is consuming a web 

service. 

You can set this trace using the -l log_level option when you start the Axis2 

server. To launch the Axis2 server with trace enable, run the following command: 

axis2_http_server -p 9876 -l 6 -f /tmp/w4gl_informix/axis_trace.log 

Use the -l to specify the logging level for the application server. The maximum 

value is 6, which enables full tracing. 

You can specify the location of the trace file using the -f log_file option. 

Example 12-34 shows the contents of a typical trace file. 

Example 12-34 A typical application_trace sample 

[debug] phase_resolver.c(139) Service name is : ws_zipcode 

[debug] phase_resolver.c(1123) Operation name is : zipcode_details 

[debug] phase_holder.c(139) Add handler AddressingOutHandler to phase 


[debug] phase_resolver.c(222) svc name is:ws_state_name 

[debug] phase_resolver.c(139) Service name is : ws_state_name 

[debug] phase_resolver.c(1123) Operation name is : state_name 


... 

For more information about the logging options with the Axis2c application 

server, refer to: 

http://ws.apache.org/axis2/c/docs/axis2c_manual.html#simple_axis_server 


Database trace 

IBM Informix 4GL uses the SQLI protocol to exchange data with the Informix 

server. Thus, any web service that is developed using Informix 4GL also uses the 

SQLI protocol for any communication with the database server. 

You can use the SQLIDEBUG environment variable to collect all the messages 

between the application server and the Informix database server. 

To enable this trace, create the SQLIDEBUG environment variable before 

starting the Axis2 Application server. 

Example 12-35 demonstrates how to set the SQLIDEBUG variable and how to 

run sqliprint to un-encode the SQLI file. 

Example 12-35 The SQLIDEBUG variable client side 

informix@irk:/usr3/4gl750/AXIS2C/bin$ export SQLIDEBUG=2:/tmp/sqlitrace 

informix@irk:/usr3/4gl750/AXIS2C/bin$ ./axis2_http_server -p 9876 

Started Simple Axis2 HTTP Server ... 

... 

... 

informix@irk:/work$ ls /tmp/sqlitrace* 

/tmp/sqlitrace_17008_0_8c819d0 

informix@irk:/works$ sqliprint -o tracefile.txt /tmp/sqlitrace_17008_0_8c819d0 

informix@irk:/works$ 

Note: The sqliprint tool is included with Informix Client Software 

Development Kit (Client SDK). 

You can also use the SQLIDEBUG trace at the server side. For more information, 

refer to 3.3.6, “Troubleshooting” on page 117. 



Chapter 13. Application development 

considerations 

13 

In this chapter, we examine some of the considerations a developer might need 

to address in a multi-user environment. A single user workstation that connects 

to an exclusive-use database does not the issue of two or more independent 

uses of the same data at the same time. However, in a multi-user environment, 

concurrency is a challenge. 

IBM Informix database servers are designed to provide features to help in 

handling concurrency and sorting facilities. The application developer should 

design applications to take advantage of these built-in features, rather than 

attempt to implement their own facilities in the application. In this chapter we 

examine the factors that cause concurrency problems, and focus on ways to 

keep the scope and duration of locks to a minimum. To do this, we consider 

isolation levels, sharing data, and data contention issues that can occur when 

two or more attempts are made to access or change the same row of data. 

In the last two sections, we focus on configuration parameters that effect the 

application development, and how to monitor issues when the application 

developers work with the database administrator to tune the engine and the 

application to work effectively. 


13.1 Concurrency and locking 

13.1.1 Types of locks 

Concurrency involves two or more independent uses of the same data at the 

same time. In a database system with many users, each user needs to be able to 

access and modify data. Unless the developer and database system impose 

controls, there can be negative consequences. Programs might access old data 

that is in the process of being changed by another user, and changes might 

seem to disappear even though it seems like the change was performed 

successfully. 

To take advantage of database server controls, tables in a multiple user 

environment should be logging tables. At a minimum, if you must use a 

nonlogging table within a transaction, either set Repeatable Read isolation level 

or lock the table in exclusive mode. 

To avoid concurrency problems, the database server imposes a system of locks. 

A lock is a claim, or reservation, that a program can place on a piece of data. The 

database server assures that no other program can modify it, as long as the lock 

is in place. When another application requests the data, the database server 

either makes the program wait or turns it back with an error. 

The application developer can control the effect of lock access using a 

combination of SQL statements and with the buffering mode selected for the 

database. The most used SQL statements are SET LOCK MODE, SET 

ISOLATION, and SET TRANSACTION. We discuss these in more detail later. 

For now, we need a better understanding of the types of locks that we can 

encounter. 

IBM Informix offers several server edition. IBM Informix Extended Parallel Server, 

Informix Online, and Standard Engine will have different syntax for concurrency 

related commands. You can find more information about the command syntax for 

the discussion in this chapter in IBM Informix Guide to SQL: Syntax, v11.50, 

SC27-3611. 

A lock is implemented as a variable associated with a data item. It can be 

explicitly placed by an application or, more frequently, is implicitly handled by the 

database management system. The lock is used to mark a data item as 

reserved; the type of lock designation determines what actions are permitted by 

users in regard to the data item. 


An IBM Informix instance can have several types of locks: 

► A shared lock reserves its object for reading only. It prevents the object from 

changing while the lock remains. More than one program can place a shared 

lock on the same object. More than one object can read the record while it is 

locked in shared mode. In the lock list output visible from onstat -k, a thread 

with a shared lock is be designated with an S. If an object is currently locked in 

exclusive mode and the user thread wants to acquire a shared lock, the 

designation is “IS” (intent-shared). 

When a session first connects to a database, IBM Informix Servers place a 

shared lock on the database, to prevent another session from acquiring an 

exclusive lock on the same database. SELECT queries place a shared lock at 

the table level, because it is faster for the engine to find a table level lock than 

it is to search through potentially thousands of row locks. 

► Intent-exclusive locks are set automatically by Informix. If a row in a table is 

updated, an exclusive lock is placed on the row and an intent-exclusive lock is 

placed on the table. This assures that no other session can place a shared or 

exclusive lock on the table as long as an individual row is locked exclusively. 

In the lock list output visible from onstat -k, a thread with an intent exclusive 

lock is designated with an IX. A related designation that is sometimes visible 

is SIX. This designation indicates the object is currently shared, with 

Intent-exclusive when the chance arrives. 

► An exclusive lock reserves its object for the use of a single application. This 

lock type is used when the application needs to change the object. You 

cannot place an exclusive lock where any other kind of lock exists. After you 

place an exclusive lock, you cannot place another lock on the same object. In 

the lock list output visible from onstat -k, a thread with an exclusive lock is 

designated with an X. 

► A promotable (or update) lock establishes an intent to update. You can only 

place it where no other updatable or exclusive lock exists. You can place an 

updatable lock on records that already have shared locks. When the 

application is about to change the locked object, you can promote the update 

lock to an exclusive lock, but only if no other locks, including shared locks, are 

on the record at the time the lock would change from update to exclusive. If a 

shared lock was on the record when the update lock was set, you must drop 

the shared lock before the update lock can be promoted to an exclusive lock. 

In the lock list output visible from onstat -k, a thread with an update lock is 

designated with an U. 

Chapter 13. Application development considerations 439

13.1.2 Lock duration 

The length of time a lock remains in effect is known as lock duration. The 

duration of a lock is determined by the application, the closing of a database, and 

the type of transaction method used by the application and database 

If the database does not use transactions (no transaction log exists and you do 

not use a COMMIT WORK statement), an explicit table lock remains until it is 

removed by the execution of the UNLOCK TABLE statement. 

If database transactions are in use, the end-of-lock-duration event occurs when 

the transaction ends or a COMMIT WORK is issued in the application. The 

ending transaction causes a release of all table, row, page, and index locks that 

were on hand during the transaction. 

13.1.3 Lock granularity 

With IBM Informix Servers, the developer can apply locks to databases, tables, 

disk pages, data rows, or index-key values. At a database level, an exclusive lock 

is simple to enforce for a developer, but it has a big impact on users. No one gets 

access until the database lock processing is completed. Concurrency drops to 

zero, and performance is maximized for the exclusive use of a single user 

running an application. 

At the other end of the granularity scope for locks, a transaction can exclusively 

lock a row, and have no impact on other users in their work efforts (if they are not 

trying to access the same row, and the lock mode is row). Concurrency is 

maximized, but performance will tend to slide as the number of users for a 

database or table increases. 

Table locks 

It is the responsibility of both database administrator and developer to select and 

enable the best level of lock granularity for users and for their database system. 

At the database level, administrative activities such as imports and exports are 

usually the task of the database administrator. For such activity, the database 

administrator would use a command such as 

DATABASE database_name EXCLUSIVE; 

Another task, principally for the database administrator, is to enable a change for 

a table or an index structure. The task of enabling work on an entire table can be 

done with a command similar to one of the following command: 

► LOCK TABLE table_name IN EXCLUSIVE MODE; 

► LOCK TABLE table_name in SHARE MODE; 


When the task is finished (end of statement or transaction reached), the table is 

implicitly unlocked. It could be unlocked explicitly with the following command: 

UNLOCK TABLE table_name; 

Note: A table lock on a table can decrease update concurrency radically. Only 

one update transaction can access that table at any given time, and that 

update transaction locks out all other transactions. However, multiple 

read-only transactions can simultaneously access the table. This behavior is 

useful in a data warehouse environment where the data is loaded and then 

queried by multiple users. 

Page locks 

Lock mode PAGE is the default for Informix tables, and it is considered the 

optimal level in lock efficiency when rows are being accessed and modified in 

physical order. If your tables are large in row count and small in row size, a page 

level lock can be severely limiting, because it will lock a large number of rows on 

a page, and discourage user access. 

In this case, it would be more efficient to change the default lock mode. For all 

new tables, this can be done by way of the Informix onconfig file, using the 

parameter DEF_TABLE_LOCKMODE. For example: 

DEF_TABLE_LOCKMODE ROW; 

Note: Use a small (or default) page size if your application contains small 

sized rows. Increasing the page size for an application that randomly 

accesses small rows can decrease performance. In addition, a page lock on a 

larger page will lock more rows, which is likely to reduce concurrency in some 

situations. 

Tables that use page locks cannot support the USELASTCOMMITTED 

concurrency feature. 

Row and key locks 

Row and key locks generally provide the best overall performance when you are 

updating a relatively small number of rows, because they increase concurrency. 

However, the database server incurs some overhead in obtaining a lock. For an 

operation that changes a large number of rows, obtaining one lock per row might 

not be cost effective. For operations that consistently change a large number of 

rows, page locks might be a better option. 


If a table is not created with row locking and you want row or key locks, you must 

alter the table. Here is an example to show how to create a table with row locking 

turned on: 

CREATE TABLE table_namer(field1 serial,field2 char(20)...) 

LOCK MODE ROW; 

The ALTER TABLE statement can also change the lock mode. An example for 

this command syntax is: 

ALTER TABLE table_name LOCK MODE (ROW); 

When the lock mode is ROW and you insert or update a row, the database server 

creates a row lock. In some cases, you place a row lock by simply reading the 

row with a SELECT statement. 

When the lock mode is ROW and you insert, update, or delete a key (performed 

automatically when you insert, update, or delete a row), the database server also 

creates a lock on the key in the index. 

Key-value locks 

When a user deletes a row within a transaction, the row cannot be locked 

because it becomes a non-existent row. However, the database server must 

somehow record that a row existed until the end of the transaction. The database 

server uses key-value locking to lock the deleted row. Key locks are used 

identically to row locks. When the table uses row locking, key locks are 

implemented as locks on imaginary rows. 

When the table uses page locking, a key lock is placed on the entire index page 

that contains the key or that would contain the key if it existed. A page lock on an 

index page can decrease concurrency more substantially than a page lock on a 

data page. Index pages are dense and hold a large number of keys. By locking 

an index page, you make a potentially large number of keys unavailable to other 

users until you release the lock. 

Note: To determine the current lock mode for a table: 

► On UNIX, try “oncheck -pt dbname:tablename | grep Locking” 

► On Windows systems, examine the output of “oncheck -pt 

dbname:tablename” 

Database locks 

The act of opening a database places a shared lock on the database name. The 

statements which open a database are CONNECT, DATABASE, or CREATE 

DATABASE. As long as a database is open, the shared lock on the database 


prevents any other program from dropping the database or putting an exclusive 

lock on it. 

Locking a database for exclusive use are not needed very often, because this 

would prevent other users and programs from accessing it for the duration of the 

lock. The usual reason for a database lock would be the need for a major 

structure change across several tables, when implementing a series of related 

indexes on several tables, or when you have an application that needs 

uninterrupted access to the database for a period of time. To lock a database in 

exclusive mode, the syntax is: 

DATABASE database_name EXCLUSIVE; 

Tasks that run from the sysadmin database (dbscheduler tasks, such as Auto 

Update Statistics), occasionally might prevent exclusive database access. In this 

case, you must temporarily disable the dbscheduler. In the sysadmin database, 

stop the scheduler API with: 

execute function task(scheduler shutdown) 

Restart the scheduler API with: 

execute function task(scheduler start) 

Smart large object locks 

Smart large objects are quite different in the way they work from the rest of the 

structures and processes in IBM Informix databases. The locking and locking 

granularity for smart large objects is also different. The database server uses one 

of the following granularity levels for locking smart large objects: 

► The sbspace chunk header partition 

► The smart large object 

► A byte range of the smart large object 

The default locking granularity for a smart BLOB is at the level of the smart large 

object. When you update a smart large object, the database server locks the 

smart large object that is being updated. Concurrently, there is an update lock 

placed on the sbspace chunk header partition while the object is being updated. 

Byte locks 

Byte locks, also known as byte-range locks, are used to lock a specific byte range 

of a smart large object. Byte-range locking is advantageous because it allows 

multiple users to update the same smart large object simultaneously, as long as 

they are updating different parts of it. Also, users can read a part of a smart large 

object while another user is updating or reading a different part of the same 



How the database server manages byte-range locks 

The database server manages byte-range locks in the lock table in a similar 

fashion to other locks placed on rows, pages, and tables. However, the lock table 

must store the byte range as well. If a user places additional locks on a byte 

range, any new byte locks in the range that are contiguous are consolidated into 

one lock range. 

Likewise, if a user unlocks a portion of the bytes included within a byte-range 

lock, the database server will split into multiple byte-range locks. 

To enable use of byte-range locks 

By default, the database server places a lock on the entire smart large object. At 

the time of sbspace creation, there is an option to use byte-range locking. 

When the DBA sets the default locking mode for the sbspace to byte-range 

locking, the database server locks only the necessary bytes when it updates any 

smart large objects stored in the sbspace. To set byte-range locking for the 

sbspace that stores the smart large object, the database administrator must use 

the onspaces utility. 

The following example sets byte-range locking for a new sbspace: 

onspaces -c -S sblob -g 2 -p /ifmx/sblob1 -o 0 -s 1000 -Df LOCK_MODE=RANGE 

When byte-range locking is set for the individual smart large object, the database 

server implicitly locks only the necessary bytes when it selects or updates the 

smart large object. The application developer can set byte-range locking for the 

smart large object when it is opened, using one of the following methods: 

► Set the MI_LO_LOCKRANGE flag in the mi_lo_open() DataBlade API function. 

► Set the LO_LOCKRANGE flag in the ifx_lo_open() ESQL/C function. 

To lock a byte range explicitly, use one of the following functions: 

► mi_lo_lock() 

► ifx_lo_lock() 

These functions lock the range of bytes that is specified for the smart large 

object. If the developer specifies an exclusive lock with either function, UPDATE 

statements do not place locks on the smart large object if they update the locked 

bytes. 

The database server releases exclusive byte-range locks placed with 

mi_lo_lock() or ifx_lo_lock() at the end of the transaction. The database 

server releases shared byte-range locks placed with mi_lo_lock() or 

ifx_lo_lock() based on the same rules as locks placed with SELECT 


statements, depending upon the isolation level. The application can also release 

shared byte-range locks with mi_lo_unlock() or ifx_lo_unlock(). 

For more information about these DataBlade API functions, see IBM Informix: 

DataBlade API Programmer's Guide: 

http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.d 

apip.doc/dapip.htm 

You can fine additional details about the ESQL/C functions in the IBM Informix: 

ESQL/C Programmer's Manual at: 

http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.e 

sqlc.doc/esqlc.htm 

13.2 Locking issues and performance 

Row and key locks generally provide the best performance whenever a database 

system only needs to update a small number of rows at a time. However, the 

database incurs additional overhead in obtaining a lock as the granularity gets 

smaller. The developer should help decide the granularity based on the character 

of the trnasactions.The following are guidelines for your decision making: 

► For low row count transactions, use row level locking. 

► For large processes that update an entire table, set locking to page or lock the 

table in exclusive mode before processing. 

► For massive updates to many tables or the whole database, lock the database 

in exclusive mode before processing. 

The type of isolation can affect overall performance because it affects 

concurrency. Before you execute a SELECT statement, you can set the isolation 

level with one of these options: 

► The SET ISOLATION statement (an extension to ANSI SQL-92 standard) 

– Can be executed more than once in a transaction. 

– Can change the enduring isolation level for a session 

– Has an additional isolation level (Cursor Stability) 

► SET TRANSACTION (ANSI/ISO-compliant) 

– Can only be executed once in a transaction. 

► Dirty Read isolation (or ANSI Read Uncommitted) level does not place any 

locks on any rows fetched during a SELECT statement. Dirty Read isolation is 

appropriate for static tables that are used for queries. Use Dirty Read isolation 

with care if update activity occurs at the same time. With Dirty Read, the 


13.2.1 Deadlocks 

reader can read a row that has not been committed to the database and might 

be eliminated or changed during a rollback. 

A deadlock is a situation in which a pair of programs blocks the progress of each 

other. Each program has a lock on some object that the other program wants to 

access. In a database with local database queries only, a deadlock arises only 

when all programs concerned set their lock modes to wait for locks. 

An Informix database server detects deadlocks immediately when they only 

involve data at a single network server. Before a lock is granted, the database 

server examines the lock list for each user. If a user holds a lock on the resource 

that the requestor wants to lock, the database server traverses the lock wait list 

for the user to see if the user is waiting for any locks that the requestor holds. If 

so, the requestor receives a deadlock error. It prevents the deadlock from 

occurring by returning an error code (error -143 ISAM error: deadlock detected) 

to the second program to request a lock. The error code is the one the program 

receives if it sets its lock mode to not wait for locks. If your program receives an 

error code related to locks even after it sets lock mode to wait, you know the 

cause is an impending deadlock. 

The best way to avoid deadlocks is to set lock mode to wait for a specific number 

of seconds (N), where N is the number of seconds it is reasonable for your 

applications to wait on a lock. Example syntax: 

SET LOCK MODE TO WAIT 30; 

Deadlock errors can be unavoidable when applications update the same rows 

frequently. However, certain applications might always be in contention with each 

other. Examine applications that are producing a large number of deadlocks and 

try to run them at different times. To monitor the number of deadlocks, monitor 

the deadlks field in the output of onstat -p. 

Distributed transactions 

Deadlock handling is more challenging when you are using a distributed query, 

which involves more than one database server. In this case, the server cannot 

monitor the locks of the other database, so deadlocks cannot be detected before 

they occur. 

Occasionally, there might be a need for each database to wait on a lock from 

another local transaction. When the wait occurs, the entire distributed transaction 

might need to wait until the action is cleared up. If both servers get into a 

wait-for-the-other-server to complete mode, you have a multi-server deadlock 

that neither server can get out of easily. 


To avoid this situation, set the DEADLOCK_TIMEOUT parameter in the onconfig 

file. This parameter tells the server how much time to wait before returning an 

error code (error -143 ISAM error: deadlock detected). For more information 

about using this configuration parameter, see IBM Informix Dynamic Server 

Administrator's Guide, v11.50, SC27-3606. 

Distributed transactions, also known as global transactions, can have additional 

problems beyond concurrency and locking. In a distributed transaction, we can 

have queries that include multiple, separate databases spanning multiple host 

systems across a network. With the added task of reaching out to different 

servers, we are confronted with delays caused by network traffic, connectivity 

issues, additional user authentication, and user activity on the other database 

server that can slow or temporarily prevent quick access to the remote database 

server. 

In the context of a query that is doing an update, insert, select, or delete, this new 

group of interfering factors can occasionally present problems. Developers 

should include coding conventions to accommodate distributed (XA) transactions 

and include code to avoid certain problems. We have included an ESQL/C 

routine (xa_tool.ec) in Appendix B, “Accommodating distributed transactions” on 

page 469 that is designed to help provide a start for handling XA problems. 

13.3 Isolation levels 

The number and duration of locks placed on data during a SELECT statement 

depends on the level of isolation that the user sets. The type of isolation can 

affect overall performance because it affects concurrency. 

You can set the isolation level with the SET ISOLATION or the ANSI SET 

TRANSACTION statement before you execute the SELECT statement. The main 

differences between the two statements are that SET ISOLATION has an 

additional isolation level, Cursor Stability, and SET TRANSACTION cannot be 

executed more than once in a transaction as SET ISOLATION can. 

Dirty Read isolation 

Dirty Read isolation (or ANSI Read Uncommitted) does not place any locks on 

any rows fetched during a SELECT statement. Dirty Read isolation is appropriate 

for static tables that are used for queries. It offers the best performance of all 

isolation levels, because the database server does not check or place any locks 

for queries. 

If update activity can occur at the same time as a dirty read, there is a chance 

that a rollback might need to occur during the dirty read. The reader could read a 


ow that has not been committed (this is known as a phantom read) to the 

database and the data would be lost during a subsequent rollback. Because of 

potential problems with uncommitted data that is rolled back, use Dirty Read 

isolation with care. 

Databases that do not have logging turned on (and thus do not allow 

transactions) use Dirty Read as a default isolation level. In fact, Dirty Read is the 

only isolation level allowed for databases that do not have logging turned on. 

Committed Read isolation 

Committed Read isolation (or ANSI Read Committed) removes the problem of 

phantom reads. A reader with this isolation level checks for locks before it returns 

a row. By checking for locks, the reader cannot return any uncommitted rows. 

The database server does not actually place any locks for rows read during 

Committed Read. It simply checks for any existing rows in the internal lock table. 

Committed Read is the default isolation level for databases with logging, and it is 

an appropriate isolation level for most activities. 

Cursor Stability isolation 

A reader with Cursor Stability isolation acquires a shared lock on the row that is 

currently fetched. This action assures that no other user can update the row until 

the user fetches a new row. 

If you do not use a cursor to fetch data, Cursor Stability isolation behaves in the 

same way as Committed Read. No locks are actually placed. 

Repeatable Read isolation 

Repeatable Read isolation (also known as ANSI Serializable and ANSI 

Repeatable Read) is the strictest isolation level. With Repeatable Read, the 

database server locks all rows examined (not just fetched) for the duration of the 

transaction. 

Repeatable Read is useful during any processing in which multiple rows are 

examined, but nothing will change during the transaction. The original application 

holds a read lock on each account that it examines until the end of the 

transaction, so the attempt by the second application to change the first account 

fails (or waits, depending upon SET LOCK MODE). 

Note: With Repeatable Read, because even examined rows are locked, if the 

database server reads the table sequentially, a large number of rows 

unrelated to the query result can be locked. 


Use Repeatable Read isolation for tables when the database server can use an 

index to access a table. If an index exists and the optimizer chooses a sequential 

scan instead, you can use directives to force use of the index. However, forcing a 

change in the query path might negatively affect query performance. 

13.4 Configuration options 

We have brought configuration parameters into our discussion several times. In 

this section, we examine IBM Informix Server configuration options that directly 

affect application development. We point out what the developers should know, 

and how these parameters affect the application and transactions. For more 

information about any of the parameters in the onconfig file or environment 

variables relating to configuration, see IBM Informix Dynamic Server 

Administrator's Reference, v11.50, SC27-3607. 

13.4.1 Server identification 

When the Informix server needs to resolve a database instance name, the 

oninit process uses the contents of a file known as the sqlhosts file. Each line 

in the sqlhosts file provides a database server naming reference, called the 

DBSERVERNAME, along with a protocol, a host system reference, and a 

listening protocol service reference. On Windows systems, this information is 

stored in the registry and is updated and accessed using the setnet32.exe utility. 

Multiple DBSERVERNAME references allow for an evenly distributed connection 

distribution over a variety of protocols 

In addition to the information in the sqlhosts file, the DBSERVERNAME crosses 

reference to the onconfig file, which holds the configuration information 

describing how the database server is to operate. When a client application 

connects to a database server, it specifies a DBSERVERNAME, which helps the 

server to know which protocol will be used for the connectivity. 

The DBSERVERNAME used in the application connection must be consistent 

with a name specified in the sqlhosts file and a DBSERVERNAME that is 

defined in the onconfig file. 

In the onconfig file, there is a default (main instance) DBSERVERNAME and one 

or more alternate DBSERVERNAME parameters that are available. The DBA 

specifies the default name to be used with the DBSERVERNAME parameter in 

the onconfig file. For alternative application processing, the DBA can allow for or 

specify alternative protocols, referenced by an a different DBSERVERNAME. 

The alternate DBSERVERNAME or names are specified by the 

DBSERVERALIASES parameter in the onconfig file. An application developer 


should check with the DBA to determine whether to use the DBSERVERNAME 

or one of the DBSERVERALIASES for connecting with his application. Example 

SQL statements include CONNECT, DATABASE, CREATE TABLE, and ALTER 

TABLE, which can specify the database server instance. 

13.4.2 Storage space identifiers 

When tables are created, the database creator has syntax options available to 

define where tables and indexes are to be placed physically in a disk structure. 

Typically, the database administrator defines the disk structure layout. The disk 

layout is assigned by way of dbspaces, and each dbspace is further broken down 

into allocations of chunks. 

The dbspace is the parent structure unit, used to hold storage information for 

tables and indexes, with low level definitions to describe where the actual data 

pointers for row data resides, as well as information about indexes, fragments, 

and table scope. The dbspace area that tracks pointer locations for data is known 

as the table space. 

When defining the table and index schema, the database administrator can 

specify a dbspace location to hold the table or the index. Other space 

specifications for default storage are available if none are specified at creation 

time. These default locations define where to store binary large objects (BLOBs), 

character large objects (CLOBs), and temporary storage locations. 

The default location for the location of temp tables and sorting space, if not 

predefined, is the dbspace where a table is accessed, or the root dbspace 

(rootdbs). If a default onconfig file definition for the location of temp dbspace is 

defined, we have more control over the location used 

The DBSPACETEMP parameter 

The DBSPACETEMP parameter specifies a list of dbspaces that the database 

server uses to globally manage the storage of temporary tables. When a 

temporary space is available, it improves performance by enabling the database 

server to spread I/O for temporary tables across multiple disks efficiently. The 

database server also uses temporary dbspaces during backups to store the 

before-images of data that are overwritten while the backup is occurring. More 

than one dbspace can be specified for this parameter. Simply list them as 

comma-separated values. 

The DBSPACETEMP parameter can contain dbspaces with a non-default page 

size, but all of the dbspaces in the DBSPACETEMP list must have the same page 

size. 


When using a logged database, file activity in temporary dbspaces is not logged. 

If the developer writes a query that requires tempspace, it is useful to include the 

phrase WITH NO LOG, so that you can force the query to use the designated 

temporary dbspace. 

The SBSPACENAME parameter 

The SBSPACENAME parameter specifies the name of the default sbspace. If 

your database tables include smart-large-object columns that do not explicitly 

specify a storage space, that data is stored in the sbspace that SBSPACENAME 

specifies. The default sbspace is also used by the built-in encryption and 

decryption functions to store BLOB or CLOB values. 

An sbspace is a specialized type of dbspace, used for storing smartblobs and 

binary large object dbspaces. (Binary data or some type of multidimensional data 

is common to any datablade that uses R-tree indexing.) 

When a create table statement includes a column that defines a CLOB or BLOB 

object, the column information will be stored in an sbspace. If the PUT clause is 

not specified in the create table statement when the defined CLOB or BLOB is 

created, the default location where the column data will be stored is the sbspace 

designated by the SBSPACENAME parameter. 

If you are using IBM Informix with J/Foundation, you must provide a smart large 

object where the database server can store the Java archive (.jar) files. These 

.jar files contain the Java user-defined routines (UDRs). If you use Java UDRs, 

you will want to create additional, separate sbspaces for storing smart large 

objects. 

The SBSPACETEMP parameter 

The SBSPACETEMP parameter specifies the name of the default temporary 

sbspace for storing temporary smart large objects without metadata or user-data 

logging. If you store temporary smart large objects in a standard sbspace, the 

metadata is logged. For more information about using temporary smart large 

objects, see IBM Informix DataBlade API Programmer's Guide, V11.50, 

SC23-9429. 

The SYSSBSPACENAME parameter 

The SYSSBSPACENAME parameter specifies the name of the sbspace in which 

the database server stores statistics that the UPDATE STATISTICS statement 

collects for certain user-defined data types. Normally, the database server places 

statistics in the sysdistrib system catalog table. 


Note: For information about writing user-defined statistics, refer to IBM 

Informix User-Defined Routines and Data Types Developer's Guide, V11.5, 

SC23-9438. 

For information about providing statistics data for a smart BLOB column, refer 

to IBM Informix DataBlade API Programmer's Guide, V11.50, SC23-9429. 

13.4.3 Limiters and limits 

In addition to the storage location identifiers mentioned in 13.4.2, “Storage space 

identifiers” on page 450, a number of parameters in the onconfig file impose 

resource limits. Limits help the engine and system to utilize appropriate 

resources rather than consume all the resources on the system and end up in a 

crash. When the resources are no longer needed, they are released to be used 

by other processes. These configuration limits can be adjusted in cooperation 

with the database administrator, to accommodate for application concerns that 

might need them. 

The MULTIPROCESSOR parameter 

The MULTIPROCESSOR parameter is used to determine the type of processing 

method the engine will use. If it is set to 0, locking is done in a way that is suitable 

for a single- processor computer, and processor affinity is ignored. 

If the nearby onconfig file SINGLECPU_VP parameter is non-zero (On), 

MULTIPROCESSOR and user-defined VPCLASSes (of any kind) will not work. 

The VPCLASS parameter 

The VPCLASS parameter allows you to designate a class of virtual processors 

(VPs), create a user-defined VP, and specify the following information for it: 

► The number of virtual processors that the database server should start 

initially. 

► The maximum number of virtual processors allowed for this class. 

► The assignment of virtual processors to CPUs if processor affinity is available. 

► The disabling of priority aging by the operating system if the operating system 

implements priority aging. 

You can have multiple VPCLASS parameter definitions. Use one VPLCLASS 

reference for each class of virtual processor, one per line. Basic guidelines for 

defining a VPLCASS are in IBM Informix Dynamic Server Administrator's 

Reference, V11.50, SC27-3607. 


For information about creating a user-defined virtual process, see IBM Informix 

User-Defined Routines and Data Types Developer's Guide, V11.5, SC23-9438 

or J/Foundation Developer's Guide, V11.5, SC23-9434. 

The NETTYPE parameter 

The NETTYPE parameter provides tuning options for the protocols that 

DBSERVERNAME entries define in the sqlhosts file or registry. Each 

DBSERVERNAME entry in the sqlhosts file or registry is defined in relation to 

either the DBSERVERNAME parameter or the DBSERVERALIASES parameter 

in the ONCONFIG file. 

The NETTYPE configuration parameter describes a network connection as 

follows: 

► The protocol (or type of connection). 

► The number of poll threads assigned to manage the connection. 

► The expected number of concurrent connections. 

► The class of virtual processor that will run the poll threads. 

► You can specify a NETTYPE parameter for each protocol that you want the 

database server to use. 

► There is a special NETTYPE setting available if you want to enable the 

database server to use multiplexed connections on UNIX. To do this, you 

designate a NETTYPE with the value sqlmux, as in the following example. 

NETTYPE sqlmux 

The LOCKS parameter 

The LOCKS parameter specifies the initial size of the lock table. Every SQL 

session that connects to a database, and accesses tables and rows, generates a 

lock. If the lock is non-exclusive, it is shared; if something needs to change, it is 

exclusive. If there is an intent to change an object, it is an intent-exclusive lock. 

The lock table holds an entry for each type of lock entry, and each of these lock 

entries will have a small allocation in resident memory. 

When the number of locks exceeds the lock table value, on 32-bit servers, the 

database server will increase the size of the lock table by doubling the lock table 

value, up to 99 times, or to the maximum value for the server allowance 

(whichever comes first). On 32-bit servers, the maximum limit is 8,000,000 locks. 

On 64-bit servers, the lock table limit is based on the maximum starting locks 

value (500,000)+99 allowed increments of 1,000,000 locks for a total of 

599,000,000 locks. 


The amount of memory storage per lock ranges from 100 to 200 bytes, 

depending on the byte-word size and the platform. 

Note: All lock table increments are kept in virtual memory. If the server engine 

has limited shared memory, locks can become a memory resource drain. 

The STACKSIZE parameter 

The STACKSIZE parameter specifies the stack size for database server user 

threads. Setting a value for STACKSIZE that is too large wastes virtual memory 

space and can cause swap-space problems. 

For 32-bit platforms, the default STACKSIZE value of 32 KB is sufficient for 

non-recursive database activity. For 64-bit platforms, the recommended 

STACKSIZE value is 64 KB. 

In recursive SQL routines, the server checks for the possibility of stack-size 

overflow and automatically expands the stack. 

UDRs should increase the stack size for a routine as needed, using the stack 

modifier in the CREATE FUNCTION statement. 

The USELASTCOMMITTED parameter 

This parameter specifies the isolation level whenever the LAST COMMITTED 

feature of the COMMITTED READ isolation level is implicitly in effect. The LAST 

COMMITTED feature can reduce the risk of locking conflicts between concurrent 

transactions on tables that have exclusive row locks. 

Important: The USELASTCOMMITTED parameter works only with tables 

that have been created or altered to have ROW as their locking granularity. 

For the USELASTCOMMITTED parameter to work as expected, and given that a 

table has been created or altered to have ROW as their locking granularity, the 

following considerations also apply: 

► If SET TRANSACTION is enabled with READ COMMITTED or READ 

UNCOMMITTED, USELASTCOMMITTED will work. 

► Tables created without any explicit lock mode setting will use the default 

setting in DEF_TABLE_LOCKMODE. 

The DEF_TABLE_LOCKMODE parameter 

The DEF_TABLE_LOCKMODE parameter sets the lock mode for every newly 

created table for all sessions connected to a logging or nonlogging database, and 

has no effect on existing tables in the database. 


The specified value can be ROW, which sets the lock mode to ROW for every 

new table connected to a database. If the specified value is PAGE (default), any 

exclusive locked table remains inaccessible. 

There is also an environment variable on the client side, 

DEF_TABLE_LOCKMODE, which can be set with a lock mode value (PAGE or 

ROW). The environment variable has rules of precedence involved if the 

onconfig value is also set. For more information, see IBM Informix Dynamic 

Server Administrator's Reference, V11.50, SC27-3607. 

The DEADLOCK_TIMEOUT parameter 

The DEADLOCK_TIMEOUT parameter specifies the maximum number of 

seconds that a database server thread can wait to acquire a lock. Use this 

parameter only for distributed queries that involve a remote database server. 

Note: This parameter applies only to distributed queries. There is a separate, 

automated mechanism for deadlocks that are internal to a local database. 

The OPTCOMPIND parameter 

The OPTCOMPIND parameter determines the method used by the engine to 

process a query. All queries are optimized to run based on the guideline 

recommended by this parameter, unless the developer forces a different 

guideline using a directive. 

When the OPTCOMPIND parameter is set to one of the following values, a given 

query is optimized using the guideline assigned: 

0 When appropriate indexes exist for tables in the query, the optimizer 

chooses index scans, without consideration of the cost, over table 

scans. 

1 As long as the isolation is not Repeatable Read, the optimizer will 

use cost based decisions. If Repeatable Read is in use, it behaves as 

though OPTCOMPIND=0. Setting 1 is recommended for optimal 

performance. 

2 The optimizer uses cost to determine an execution path regardless of 

isolation level. Index scans are not given preference; the optimizer 

decision is purely based on cost. Setting 2 is the default if the 

parameter is not set. 

Note: Use the same OPTCOMPIND value in the development and in the 

production environment. Performance and query behavior can have variations 

if the OPTCOMIND value is different in the development and production 

environments. 


The DIRECTIVES parameter 

The DIRECTIVES parameter enables or disables the use of SQL directives. SQL 

directives allow you to specify behavior for the query optimizer in developing 

query plans for SELECT, UPDATE, and DELETE statements. 

Set DIRECTIVES to 1, which is the default value, to enable the database server 

to process directives. 

Set DIRECTIVES to 0 to disable the database server from processing directives. 

Note: Client programs have the option to set the IFX_DIRECTIVES 

environment variable to ON or OFF to enable or disable processing of 

directives by the database server. The setting of the IFX_DIRECTIVES 

environment variable overrides the setting of the DIRECTIVES configuration 

parameter. If you do not set the IFX_DIRECTIVES environment variable, all 

sessions for a client inherit the database server configuration for processing 

SQL directives. 

The MAX_PDQPRIORITY parameter 

The MAX_PDQPRIORITY parameter limits the PDQ resources that the database 

server can allocate to a given DSS query. MAX_PDQPRIORITY is a factor that is 

used to scale the value of PDQ priority set by users. For example, if the database 

administrator sets MAX_PDQPRIORITY to 80, and a user sets the 

PDQPRIORITY environment variable to 50 and issues a query, the database 

server silently processes the query with a PDQ priority of 40. The database 

administrator can use the onmode utility to change the value of 

MAX_PDQPRIORITY while the database server is online. 

In Informix database server, PDQ resources include memory, CPU, disk I/O, and 

scan threads. the MAX_PDQPRIORITY parameter lets the database 

administrator run decision support concurrently with OLTP, without a 

deterioration of OLTP performance. However, if the MAX_PDQPRIORITY 

parameter is too low, the performance of decision- support queries can degrade. 

Table 13-1 lists the MAX_PDQPRIORITY value that you can set. 

Table 13-1 The MAX_PDQPRIORITY value 

Value Database Server Action 

0 Turns off PDQ. DSS queries use no parallelism. 

1 Fetches data from fragmented tables in parallel (parallel scans) but 

uses no other form of parallelism. 

100 Uses all available resources for processing queries in parallel. 


Value Database Server Action 

An integer 

between 1-100 

13.4.4 Java configuration parameters 

The configuration parameters listed in Table 13-2 allow you to use J/Foundation, 

which incorporates an embedded Java Virtual Machine (JVM) on the database 

server. For more information about these parameters, see J/Foundation 

Developer's Guide, V11.5, SC23-9434. 

Table 13-2 Java configuration parameters 

Parameter name Description 

Sets the percentage of the user-requested PDQ resources to be 

allocated to the query. 

AFCRASH 0x10 When the 0x10 bit is on for AFCRASH, all the messages that the 

JVM generates are logged into the JVM_vpid file, where vpid is 

the process ID of the Java virtual processor. This file is stored in 

the directory where the JVPLOG file is stored. 

JVPDEBUG When set to 1, tracing messages are written to the JVPLOG file. 

JVPHOME Directory where the classes of the IBM Informix JDBC Driver are 

installed. 

JVPLOGFILE Absolute path name for your Java VP log files. 

JVPPROPFILE Absolute path name for the Java VP properties file. 

JVPJAVAVM Libraries to use for the JVM. 

JVPJAVAHOME Directory where the Java Runtime Environment (JRE) for the 

database server is installed. 

JVMTHREAD Thread package (green or native) to use for the JVM. 

JVPVJAVALIB Path from JVPJAVAHOME to the location of the Java VM 

libraries. 

JVPCLASSPATH Initial Java class path setting. 

VPCLASS jvp=n Number of Java virtual processors that the database server 

should start. 

For additional onconfig file parameters and how they relate to development, see 

Appendix A, “Parameters in the onconfig file” on page 467. 


13.5 Working with your database administrator 

There is an assumption throughout this book that our main audience is the 

developer, with a distinctive separate role from the database administrator (DBA). 

The database server administrator has the task of allocating and handling 

resources effectively in the server side of a client -server environment. When a 

performance issue occurs or when a transaction process is not working as it 

should, you need to work with the database administrator to find a solution. 

Present the problem to the database administrator, who might have a good idea 

about a particular configuration area that might relate to the problem. There are a 

few areas we can discuss here, which might help target the common problems 

that developers experience. 

Configuration parameters that affect logging 

Checkpoints, logging, and page cleaning are necessary to maintain database 

consistency. A direct trade-off exists between the frequency of checkpoints or the 

size of the logical logs and the time that it takes to recover the database in the 

event of a failure. A database administrator has to consider ways to reduce the 

overhead for these activities based on the acceptable delay during recovery. 

Sometimes these decisions are influenced by the behavior of the application. 

Here we discuss the configuration parameters that effect logging. 

LOGBUFF and PHYSBUFF 

The LOGBUFF and PHYSBUFF configuration parameters effect logging I/O 

activity because they specify the respective sizes of the logical-log and 

physical-log buffers that are in shared memory. The size of these buffers 

determines how quickly they fill and therefore how often they need to be flushed 

to disk. If checkpoints tend to have long duration, you can seek further 

information related to buffer tuning and checkpoint tuning information in the IBM 

Informix Dynamic Server Performance Guide, V11.50, SC27-3618-00. 

LOGFILES 

The LOGFILES parameter specifies the number of logical-log files. This 

parameter only becomes important with respect to the long transaction high 

water mark (LTXHWM and LTXEHWM), if we are having trouble with transactions 

that need to be rolled back. See the sections on DYNAMIC_LOGS, LTXHWM 

and LTXEHWM, later in this chapter for more details. 

LOGSIZE 

Choose a log size based on how much logging activity occurs and the amount of 

risk in case of catastrophic failure. If you cannot afford to lose more than an 

hour's worth of data, create many small log files that each hold an hour's worth of 


transactions. If your system is stable with high logging activity, choose larger logs 

to improve performance. 

Note: A backup process can hinder transaction processing if data is located 

on the same disk as the logical-log files. It is better to keep logical logs on 

separate disks from data, if possible. If extra disks are not an option for 

separate logical log space, however, you can wait for periods of low user 

activity before you back up the logical-log files. 

You need to adjust the size of the logical log when your transactions include 

simple large objects or smart large objects, as the following sections describe. 

Estimating logical-log size when logging simple large objects 

To obtain better overall performance for applications that perform frequent 

updates of TEXT or BYTE data in blobspaces, reduce the size of the logical log. 

Blobpages cannot be reused until the logical log to which they are allocated is 

backed up. When TEXT or BYTE data activity is high, the performance impact of 

more frequent checkpoints is balanced by the higher availability of free 

blobpages. 

When you use volatile blobpages in blobspaces, smaller logs can improve 

access to simple large objects that must be reused. Simple large objects cannot 

be reused until the log in which they are allocated is flushed to disk. In this case, 

you can justify the cost in performance because those smaller log files are 

backed up more frequently. 

Estimating logical-log size when logging smart large objects 

If you plan to log smart large object user data, you must ensure that the log size 

is considerably larger than the amount of data being written. Smart large object 

metadata is always logged even if the smart large objects are not logged. 

Use the following guidelines when you log smart large objects: 

► If you are appending data to a smart large object, the increased logging 

activity is roughly equal to the amount of data written to the smart large 

object. 

► If you are updating a smart large object (overwriting data), the increased 

logging activity is roughly twice the amount of data written to the smart large 

object. The database server logs both the before-image and after-image of a 

smart large object for update transactions. When updating the smart large 

objects, the database server logs only the updated parts of the before and 

after image. 


► Metadata updates affect logging less. Even though metadata is always 

logged, the number of bytes that are logged is usually much smaller than the 

smart large objects. 

The DYNAMIC_LOGS parameter 

The default value for the DYNAMIC_LOGS configuration parameter is 2, which 

means that the database server allocates a new logical log file automatically after 

the current log file when it detects that the next log file contains an open 

transaction. The database server automatically checks whether the log after the 

current log still contains an open transaction at the following times: 

► Immediately after it switches to a new log file while writing log records (not 

while reading and applying log records) 

► At the beginning of the transaction cleanup phase which occurs as the last 

phase of logical recovery 

Logical recovery happens at the end of fast recovery and at the end of a cold 

restore or roll forward. For more information about the phases of fast recovery, 

see IBM Informix Dynamic Server Administrator's Guide, Version 11.50, 

SC27-3606. 

If you set DYNAMIC_LOGS to 0, the database server still checks whether the 

next active log contains an open transaction when it switches log files. If it finds 

an open transaction in the next log to be active, it issues the following warning: 

WARNING: The oldest logical log file (%d) contains records from an open 

transaction (0x%p), but the Dynamic Log Files feature is turned off. 

The LTXHWM and LTXEHWM parameters 

The LTXHWM parameter indicates how full the logical log is when the database 

server starts to check for a possible long transaction and to roll it back. 

LTXEHWM indicates the point at which the database server suspends new 

transaction activity to locate and roll back a long transaction. 

With the dynamic log file feature, long transaction high watermarks are no longer 

as critical because the database server does not run out of log space unless you 

use up the physical disk space available on the system. Under normal conditions, 

you should keep the default values for LTXHWM and LTXEHWM. If a rollback is 

ever needed, it can indicate a serious problem within an application. 


After Version 9.4, LTXHWM and LTXEHWM are not in the onconfig.std file and 

default to the following values, depending on the value of the DYNAMIC_LOGS 

configuration parameter: 

► With DYNAMIC_LOGS set to 1 or 2, the long transaction high watermark 

default values are 80 for LTXHWM and 90 for LTXEHWM. Because the 

database server does not run out of logs, other users can still access the log 

during the rollback of a long transaction. 

► With DYNAMIC_LOGS to 0, the default values are 50 for LTXHWM and 60 for 

LTXEHWM. 

You might want to change these default values for one of the following reasons: 

► To allow other transactions to continue update activity (which requires access 

to the log) during the rollback of a long transaction. In this case, you increase 

the value of LTXEHWM to raise the point at which the long transaction 

rollback has exclusive access to the log. 

► To perform scheduled transactions of unknown length, such as large loads 

that are logged. In this case, you increase the value of LTXHWM so that the 

transaction has a chance to complete before reaching the high watermark. 

13.5.1 Parameters for negotiation 

While the database administrator should make final decisions for server 

parameters, there are several parameters for which you need agreement to 

achieve the most effective results. 

The VPCLASS parameter 

If you decide to use UDRs, a UDR can use the processing power in the CPU 

class that users currently have at their disposal, or you can define the UDR with 

its own processor class when you create the function. You define a new class of 

virtual processors to isolate UDR execution from other transactions that execute 

on the CPU virtual processors. This method is typically used when you write 

UDRs to support user-defined data types. The class name that you specify in the 

VPCLASS parameter must match the name specified in the CLASS modifier of 

the CREATE FUNCTION statement. 

Note: Because a user-defined CPU class is treated as a virtual processor, the 

onconfig file SINGLE_CPU_VP parameter must be off (0) and 

MULTIPROCESSOR must be on (1). 


Guidelines for setting VPCLASS: 

► For uniprocessor computers, it is recommended that you use one CPU virtual 

processor. 

► VPCLASS cpu,num=1. 

► For multiprocessor systems with four or more CPUs that are primarily used as 

database servers, it is recommended that you set the VPCLASS num option to 

one less than the total number of processors. For example, if you have four 

CPUs, use the following specification: 

VPCLASS cpu,num=3 

Process priority aging 

On some operating systems, priority aging occurs when the operating system 

lowers the priority of long-running processes as they accumulate processing 

time. Always disable the priority aging parameter of VPCLASS because it can 

cause the performance of the database server processes to decline over time. 

For further information, check the system notes for your database server. 

Processor affinity 

Processor affinity distributes the computation impact of CPU virtual processors 

and other processes. On computers that are dedicated to the database server, 

assigning CPU virtual processors to all but one of the CPUs achieves maximum 

CPU utilization. On computers that support both database server and client 

applications, you can bind applications to certain CPUs through the operating 

system. By doing so, you effectively reserve the remaining CPUs for use by 

database server CPU virtual processors, which you bind to the remaining CPUs 

with the VPCLASS configuration parameter. 

Set the aff option of the VPCLASS parameter to the numbers of the CPUs on 

which to bind CPU virtual processors. For example, on an 8 CPU system, the 

following VPCLASS setting assigns CPU virtual processors to processors 4 to 7, 

and CPU’s 0, 1, 2, and 3 would be most available to the application: 

VPCLASS cpu,num=4,aff=4-7 

For additional methods that can be used with the VPCLASS, see IIBM Informix 

Dynamic Server Administrator's Guide, V11.50, SC27-3606. 

13.5.2 Monitoring isolation levels 

As a general discovery tool, the onstat -g sql command can be used for 

determining the isolation levels and lock modes for SQL statements actively 

running against the server, their associated databases and any SQL errors that 

might have occurred. The onstat -g sql command can also be run with an 


optional session ID. The output contains the most recent and the current SQL 

statements being run by the session. 

13.5.3 Monitoring locks 

The onstat -k command displays the current database locks held within the 

system. The type of lock is determined by the logging mode, isolation levels, and 

application design. Example 13-1shows the output of a sample onstat -k 

command. 

Example 13-1 The onstat -k command output 

IBM Informix Dynamic Server Version 11.50.UC6 -- On-Line -- Up 03:55:17 -- 

15360 Kbytes 

Locks 

address wtlist owner lklist type tblsnum rowid key#/bsiz 

a095f78 0 a4d9e68 0 HDR+S 100002 203 0 

1 active, 2000 total, 2048 hash buckets, 0 lock table overflows 

The information in this output explains lock aspects. The type column explains 

the lock types associated with each open lock. The abbreviations in the Type 

column defines lock types as follows: 

HDR Header 

B Byte lock 

S Shared 

I Intent 

X Exclusive 

U Update 

IX Intent exclusive 

IS Intent-shared 

SIX Shared, Intent exclusive 


The lock level is determined by the value of the tblsnum (tblspace ID) and the row 

ID as show in Table 13-3 and Table 13-4. 

Table 13-3 Determining lock level from Row ID 

If RowID Lock level is 

Equals 0 Table 

Ends in 00 Page 

– X=transaction cleanup 

– Y=condition 

Watch for persistent L, S, T, or Y. 

3. Look at flag position 3 (thread activity): 

– A=DBSpace backup 

– B=Begin work 

– P=Preparing/prepared 

– X=XA prepare 

– C=Commiting/committed 

– R=Aborting/aborted 

– H=Heuristic aborting/aborted 

Watch for P, X, C, R, H. 

For more information about onstat commands and the meanings of the columns, 

refer to: 


adref.doc/ids_adr_0608.htm 



A 

Appendix A. Parameters in the onconfig 

file 

In 13.4, “Configuration options” on page 449, we discuss several parameters that 

have a direct impact on developer methods and understandings. The list 

provided in that section is limited to the direct-impact related parameters. It is 

likely that application developers will not have much use for the remaining 

onconfig parameters most of the time. 

Normally, this remaining configuration information is a concern only for the DBAs. 

Occasionally, there will come a time when performance of an application might 

come into question. Sometimes slow performance is caused by the application, 

and is under control of the developer. At other times it might be an onconfig file 

setting in the IBM Informix server that requires adjustment. 

Table A-1 on page 468 lists the parameters that might help developers and DBAs 

to narrow the target area for further investigation. The table is not an exhaustive 

list. Parameters that do not apply or that we have already discussed in this book 

are not listed. For further information about any of these parameters, see IBM 

Informix Dynamic Server Administrator's Reference, v11.50, SC27-3607. 

From the developer’s point of view, it makes sense to categorize the configuration 

parameters from a functional perspective, rather than a strict listing by name. 

Toward this objective, the parameter names are listed in the table by function 

groupings to help narrow down the parameter list that can be considered for an 


area of specific interest. The functional groupings do not reflect specific naming 

conventions used in the onconfig file. 

Table A-1 Parameters in the onconfig file 

Related function area Parameters 

Storage Space ROOTNAME, ROOTOFFSET, ROOTSIZE, MIRROR, 

MIRROROFFSET, LOGFILES, LOGSIZE, 

DBSPACETEMP, SBSPACETEMP, SBSPACENAME, 

SYSSBSPACENAME, CLEANERS, STAGEBLOB, 

TBLTBLFIRST, TBLTBLNEXT, DATASKIP 

Path locations ROOTPATH, JVPJAVALIB, JVPJAVAVM, MSGPATH, 

PLOG_OVERFLOW_PATH 

Buffer Movement BUFFERPOOL,PHYSBUFF, PHYSFILE 

Memory Cache DD_HASHSIZE, DD_HASHMAX, DS_HASHSIZE, 

DS_POOLSIZE, PC_HASHSIZE, PC_POOLSIZE, 

STMT_CACHE, STMT_CACHE_HITS, 

STMT_CACHE_SIZE, STMT_CACHE_NOLIMIT, 

STMT_CACHE_NUMPOOL, PLCY_POOLSIZE, 

PLCY_HASHSIZE, USRC_POOLSIZE, 

USRC_HASHSIZE 

Memory control RESIDENT, SHMVIRTSIZE, SHMADD, EXTSHMADD, 

SHMTOTAL, SHMVIRT_ALLOCSEG, 

SHMNOACCESS,VP_MEMORY_CACHE_KB, 

ONLIDX_MAXMEM 

Virtual processor and 

connection 


NETTYPE, LISTEN_TIMEOUT, 

MAX_INCOMPLETE_CONNECTIONS, FASTPOLL, 

MULTIPROCESSOR, VPCLASS, SINGLE_CPU_VP, 

AUTO_AIOVPS, DIRECT_IO 

SQL Control LOCKS, OPTCOMPIND, DIRECTIVES, 

EXT_DIRECTIVES, OPT_GOAL, IFX_FOLDVIEW, 

RA_PAGES, RA_THRESHOLD 

Transaction control DEF_TABLE_LOCKMODE, BLOCKTIMEOUT, 

TXTIMEOUT, HETERO_COMMIT, 

DEADLOCK_TIMEOUT, DYNAMIC_LOGS, LOGBUFF, 

LTXHWM, LTXEHWM, TEMPTAB_NOLOG, 

AUTO_REPREPARE 

Decision support DS_MAX_QUERIES, DS_TOTAL_MEMORY, 

DS_MAX_SCANS, DS_NONPDQ_QUERY_MEM

B 

Appendix B. Accommodating distributed 

transactions 

This appendix discusses the use of distributed transactions with an IBM Informix 



B.1 Distributed transactions 

A transaction is a series of actions performed as a single logical unit of work in 

which either all of the actions are performed or none of them are. 

A distributed transaction is a transaction that runs in multiple processes, usually 

on several systems, and normally involves actions against two or more 

databases. Each participant of a distributed transaction must agree to commit 

the changes before the distributed transaction can be committed. 

There are three core components on a distributed transaction: 

► Application program (AP) 

Application program implements the desired business function. It specifies a 

sequence of operations that involve resources such as databases. An 

application program participates in one or more units of work, and might 

decide to commit or roll back each unit of work independently. 

► Resource manager (RM) 

Resource manager manages access to shared resources such as databases. 

The resource manager provides the services to manage the data involved in 

the distributed transaction. 

► Transaction manager (TM) 

Transaction manager manages global transactions and coordinates the 

decision to commit them or roll them back ensuring their atomicity. The 

transaction manager also coordinates recovery activities of the resource 

managers when necessary, such as after a component failure. 

The XA standards, set forth by the Open Group's X/Open Distributed Transaction 

Processing (DTP) model, define the interfaces between the transaction manager, 

the application program, and the resource manager in a DTP environment. 

These interfaces are implemented in the Informix TP/XA Interface Library. 

B.2 TP/XA Transaction Manager XA Interface Library 

TP/XA is a library of functions that allows the IBM Informix database server act 

as a resource manager in the X/Open DTP environment.The TP/XA library 

facilitates communication between a third-party transaction manager and the 


TP/XA is supplied with IBM Informix ESQL/C, which is included with Informix 

Client Software Development Kit (Client SDK). 


In addition to the TP/XA library, a header file xa.h, is supplied that contains the 

definition for the functions and common structures, such as XID or xa_switch_t, 

which are used by the transaction manager and resource manager. 

Table B-1 describes the functions used to work with XA transactions. 

Table B-1 TP/XA macro definitions 


xa_open() Initializes the resource manager (database server) for an XA 

transaction 

xa_close() Close a currently open resource manager 

xa_start() Starts an XA transaction 

xa_end() Dissociates from an XA transaction 

xa_rollback() Tells the resource manager to roll back an XA transaction 

xa_prepare() Asks the resource manager to prepare to commit an XA 

transaction 

xa_commit() Tells the resource manager to commit an XA transaction 

xa_recover() Obtains a list of XIDs that are currently in a prepared or 

heuristically completed state 

xa_forget() Tells the resource manager to forget a heuristically completed 

transaction 

xa_complete() Test Completion of asynchronous XA Request. This function is 

provided only for compliance with the X/Open XA Specification 

B.3 XA_TOOL ESQL/C sample 

Example B-1is a basic ESQL/C application which demonstrates how to use 

some of the TP/XA functions such as xa_prepare() and xa_rollback() to 

perform operations with a distributed transaction. 

Example B-1 The xa_tool.ec application 

/************************************************************* 

* 

* WARNING: USE OF THIS PROGRAM MAY HAVE UNDESIRABLE AFFECTS 

* TO THE DATABASE SERVER, INCLUDING DATA CORRUPTION!! 

* 

* TITLE: xa_tool.ec 

* 

Appendix B. Accommodating distributed transactions 471

* Compile with: 

* on UNIX systems: 

* esql -o xa_tool xa_tool.ec -lifxa 

* on Windows systems 

* esql xa_tool.ec 

* 

* This program will connect to a global transaction branch 

* and let the user manipulate the transaction. 

* 

* Usage: 

* xa_tool 

* 

* The fID, gtl, bql, and hex data should be provided from the 

* transaction desired to be manipulated. The information is 

* found by execution of the onstat -G command. Example output 

* of the onstat -G command: 

* 

* Global Transaction Identifiers 

* address flags fID gtl bql data 

* cb2a964 0x8442a 0 2 4 4D4E4F000000 

* 1 active, 128 total 

* 

* If transaction cb2a964 is the transaction that is desired 

* to be manipulated, then this program should be executed 

* with the following command: 

* 

* xa_tool 0 2 4 4D4E4F000000 

* 

* 

************************************************************* 

*/ 

#include 

#include 

#include 

#include "xa.h" 

extern struct xa_switch_t infx_xa_switch; 

#define xa_open(info, rmid, flags) \ 

((*infx_xa_switch.xa_open_entry)(info,rmid,flags)) 

#define xa_start(gtrid,rmid, flags) \ 

((*infx_xa_switch.xa_start_entry)(gtrid,rmid,flags)) 

#define xa_rollback(gtrid,rmid, flags) \ 

((*infx_xa_switch.xa_rollback_entry)(gtrid,rmid,flags)) 

#define xa_commit(gtrid,rmid, flags) \ 

((*infx_xa_switch.xa_commit_entry)(gtrid,rmid,flags)) 

#define xa_rollback(gtrid,rmid, flags) \ 

((*infx_xa_switch.xa_rollback_entry)(gtrid,rmid,flags)) 

#define xa_end(gtrid,rmid, flags) \ 

((*infx_xa_switch.xa_end_entry)(gtrid,rmid,flags)) 

#define xa_prepare(gtrid,rmid, flags)\ 

((*infx_xa_switch.xa_prepare_entry)(gtrid,rmid,flags)) 


#define xa_close(info,rmid, flags)\ 

((*infx_xa_switch.xa_close_entry)(info,rmid,flags)) 

#define xa_forget(gtrid,rmid, flags)\ 

((*infx_xa_switch.xa_forget_entry)(gtrid,rmid,flags)) 

#define xa_recover(gtrid, count, rmid, flags)\ 

((*infx_xa_switch.xa_recover_entry)(gtrid,count,rmid,flags)) 

/* Doesn't matter what database is opened... */ 

#define OPEN_DATABASE "sysmaster" 

/* Initialize the xid */ 

void 

setup_myxid (XID *xid, int x_fID, int x_gtl, int x_bql, char* x_data) 

{ 

int ii, c; 

xid->formatID = x_fID; 

xid->gtrid_length = x_gtl; 

xid->bqual_length = x_bql; 

} 

for(ii=0; iidata[ii] = (char) c; 

void xa_tool(XID *xid) 

{ 

int choice = 0; 

int cc; 

while( choice != 'Q') 

{ 

printf("\tP -- XA_PREPARE\n"); 

printf("\tC -- XA_COMMIT\n"); 

printf("\tR -- XA_ROLLBACK\n"); 

printf("\tF -- XA_FORGET\n"); 

printf("\tQ -- terminate program\n"); 

printf("Enter Choice: "); 

choice = getchar(); 

choice = toupper(choice); 

printf("%c\n\n", choice); 

switch(choice) 

{ 

case 'P': 

printf("Executing XA_PREAPRE\n"); 

if ((cc = xa_prepare(xid, 0, TMNOFLAGS)) != XA_OK) 


} 

{ 

printf("XA_PREPARE failed with %d\n", cc); 

} 

else 

printf("... XA_PREPARE finished\n\n"); 

break; 

case 'C': 

printf("Executing XA_COMMIT\n"); 

if ((cc = xa_commit(xid, 0, TMNOFLAGS)) != XA_OK) 

{ 

printf("XA_COMMIT failed with %d\n", cc); 

} 

else 

printf("... XA_COMMIT finished\n\n"); 

break; 

case 'R': 

printf("Executing XA_ROLLBACK\n"); 

if ((cc = xa_rollback(xid, 0, TMNOFLAGS)) != XA_OK) 

{ 

printf("XA_ROLLBACK failed with %d\n", cc); 

} 

else 

printf("... XA_ROLLBACK finished\n\n"); 

break; 

case 'F': 

printf("Executing XA_FORGET\n"); 

if ((cc = xa_forget(xid, 0, TMNOFLAGS)) != XA_OK) 

{ 

printf("XA_FORGET failed with %d\n", cc); 

} 

else 

printf("... XA_FORGET finished\n\n"); 

break; 

case 'Q': 

break; 

default: 

printf("%c is not a valid option!\n\n", choice); 

choice = 0; 

} 

if (choice != 'Q') { 

choice = getchar(); 

choice = 0; 

} 

} 

int main(int arc, char *argv[]) 

{ 

$int cc; 

XID xid; 

int xid_fID, xid_gtl, xid_bql; 

char xid_data[300]; 


} 

if (arc != 5) 

{ 

printf("Error: Incorrect number of parameters.\n"); 

printf("Usage: %s \n", argv[0]); 

exit(2); 

} 

printf("\n\n"); 

xid_fID = atoi(argv[1]); 

xid_gtl = atoi(argv[2]); 

xid_bql = atoi(argv[3]); 

strcpy(xid_data, argv[4]); 

/* setup the XID which is used to identify the transaction */ 

setup_myxid(&xid, xid_fID, xid_gtl, xid_bql, xid_data); 

/* establish connection to the database */ 

printf("Calling xa_open ... \n"); 

if ((cc = xa_open(OPEN_DATABASE, 0, TMNOFLAGS)) != XA_OK) 

{ 

printf("xa_open failed with %d, sqlcode = %d\n", cc, SQLCODE); 

exit(1); 

} 

else 

printf("... xa_open finished\n\n"); 

/** This is for xa_tool... **/ 

xa_tool(&xid); 

/* close the connection */ 

printf("Calling xa_close...\n"); 

if ((cc = xa_close("", 0, TMNOFLAGS)) != XA_OK) 

{ 

printf("xa_close failed with %d\n", cc); 

exit(1); 

} 

else 

printf("... xa_close finished\n\n"); 

You also can use the xa_tool example to complete unresolved transactions left 

in the database server. Local transactions are rolled back automatically by the 

Informix database server if the connection between the client application and the 

database server is lost. This roll back occurs because the database server is in 

direct control of the transaction. 


When using distributed transactions, the database server cannot resolved a 

transaction automatically. The Transaction Manager is the only process in charge 

of committing or aborting the global transaction. Thus, if there is a 

communication error or a failure within the resource manager, there is a chance 

of leaving unresolved transactions in the database server. These transactions 

can be resolved using the xa_commit(), xa_rollback(), and xa_forget() 

functions. 

Example B-2 shows how to compile and use the xa_tool.ec program to rollback 

an XA transaction left in the Informix database server. 

Example B-2 The xa_tool.ec program output 

D:\Infx\ids1150>onstat -G 

IBM Informix Dynamic Server Version 11.50.FC6 -- On-Line -- Up 05:04:17 

Global Transaction Identifiers 

address flags isol timeout fID gtl bql data 

83246d88 -L--G COMMIT 0 0 2 4 4D4E4F000000 

1 active, 128 total 

D:\Infx\ids1150> 

C:\work>esql -nologo xa_tool.ec 

IBM Informix CSDK Version 3.50, IBM Informix-ESQL Version 3.50.TC7 

xa_tool.c ... 

C:\work>xa_tool 0 2 4 4D4E4F000000 

Calling xa_open ... 

... xa_open finished 

P -- XA_PREPARE 

C -- XA_COMMIT 

R -- XA_ROLLBACK 

F -- XA_FORGET 

Q -- terminate program 

Enter Choice: R 

R 

Executing XA_ROLLBACK 

... XA_ROLLBACK finished 

P -- XA_PREPARE 

C -- XA_COMMIT 

R -- XA_ROLLBACK 

F -- XA_FORGET 

Q -- terminate program 


Enter Choice: q 

Q 

Calling xa_close... 

... xa_close finished 

C:\work> 

For more information related to the TP/XA library, refer to the TP/XA Transaction 

Manager XA Interface Library User Manual at: 

http://publibfp.boulder.ibm.com/epubs/pdf/5193.pdf 



Related publications 

We consider the publications that we list in this section particularly suitable for a 

more detailed discussion of the topics that we cover in this book. 

IBM Redbooks publications 

For information about ordering these publications, see “How to get IBM 

Redbooks publications” on page 480. Note that some of the documents that we 

reference here might be available in softcopy only. 

► Embedding Informix Dynamic Server: An Introduction, SG24-7666 

Other publications 

The following publications are also relevant as further information sources: 

► IBM Informix Dynamic Server Administrator’s Guide, v11.50, SC23-7748 

► IBM Informix Guide to SQL: Reference, v11.50, SC23-7750 

► Embedded SQLJ User’s Guide, Version 2.90, G251-2278 

► IBM Informix Storage Manager Administrator’s Guide, v2.2, G229-6388 

► IBM Informix Security Guide, v11.50, SC23-7754 

► IBM Informix GLS User’s Guide, G229-6373 

► IBM Informix Dynamic Server Administrator’s Reference, SC23-7749 

► IBM Informix Guide to SQL: Syntax, v11.50, SC23-7751 

► IBM Informix Guide to SQL: Tutorial, G229-6427 

► IBM Informix Dynamic Server Performance Guide, v11.50, SC23-7757 

► IBM Informix High-Performance Loader User’s Guide, v11.50, SC23-9433 

► IBM Informix Migration Guide, SC23-7758 

► IBM Informix JDBC Driver Programmer’s Guide, SC23-9421 

► IBM Informix ESQL/C Programmer’s Manual, v3.50, SC23-9420 

► IBM Data Server Provider for .NET Programmer’s Guide, SC23-9848 


Online resources 

► IBM Informix Dynamic Server Installation Guide for UNIX, Linux, and Mac OS 

X, GC23-7752 

► IBM Informix DB-Access User’s Guide, SC23-9430 

► IBM Informix ODBC Driver Programmer’s Manual, SC23-9423 

► IBM Informix Dynamic Server Installation Guide for Windows, GC23-7753 

► Guide to Informix MaxConnect, Version 1.1, G251-0577 

► IBM Informix Backup and Restore Guide, v11.50, SC23-7756 

► IBM Informix Dynamic Server Enterprise Replication Guide, v11.50, 

SC23-7755 

► “Expand transaction capabilities with savepoints in Informix Dynamic Server” 

by Uday B. Kale in IBM developerWorks, 26 March 2009: 

http://www.ibm.com/developerworks/data/library/techarticle/dm-0903idssavepo 

ints/index.html 

The following website is also relevant as further information sources: 

► IBM Informix Dynamic Server v11.50 Information Center: 

http://publib.boulder.ibm.com/infocenter/idshelp/v115/index.jsp 

How to get IBM Redbooks publications 

Help from IBM 

You can search for, view, or download Redbooks, Redpapers, Technotes, draft 

publications and Additional materials, as well as order hardcopy Redbooks 

publications, at this website: 


IBM Support and downloads 

ibm.com/support 

IBM Global Services 

ibm.com/services 


Index 

Symbols 

.4cf extension 418 

.ec 128 

.ecp 128 

.NET connection string attributes 

Client_Locale 259 

Connection Lifetime 259 

DB_LOCALE 259 

DELIMIDENT 259 

Enlist 259 

Fetch Buffer Size 260 

Host 260 

Max Pool Size 260 

OPTOFC 260 

Packet Size 260 

Pooling 260 

PWD 260 

Skip Parsing 260 

UserDefinedTypeFormat 260 

XCL 260 

Numerics 

4GL 15 

A 

access method 333 

ACE Report Writer 9 

ad hoc queries 7 

adapter script 370 

ADO interface 

IAccessor 220 

IColumnsInfo 220 

ICommand 220 

IDBCreateCommand 220 

IDBCreateSession 220 

IDBDataSourceAdmin 220 

IDBProperties 220 

IErrorLookup 220 

IGetDataSource 220 

IRowsetIdentity 220 

ISessionProperties 220 

ITransaction 220 

ADO object 217 

adOpenDynamic cursor 224 

adOpenForwardOnly cursor 224 

adOpenKeyset cursor 224 

adOpenStatic cursor 224 

annotation 211 

ANSI serializable 448 

antlr-2.7.6.jar 193 

Apache Web Server 295, 297, 299, 303 

application programming interface 14 

application-programming interface 35 

attribute 190 

authorized user 5 

AutoCommit mode 171 

AXIS2C_HOME 403 

B 

backup 330 

begin work 140 

BeginTransaction method 274 

BeginTransaction() 265 

bigint data type 80 

bigserial data type 80 

binary import routine 333 

binary large object 450 

binary receive routine 333 

binary send routine 333 

bind parameter 308 

bladelet 359 

BLOB 80, 178, 180, 232, 276, 314, 450 

BOOLEAN 80 

Boolean UDR 333 

buffered logging 20 

built-in data type 330 

bulk load 9 

byte 80 

byte column 7 

byte-range lock 443 

byte-range locking 444 

C 

call level interface 15 

CallableStatement object 173 


cast function 332 

cast support function 348 

certified file 183 

character large object 350, 450 

chunk 450 

CLASSPATH environment variable 157 

classpath environment variable 52, 195 

CLI 15 

CLI parameters 

database 73 

hostname 73 

port 73 

protocol 73 

client connectivity 7 

client locale 62 

Client SDK 9, 11, 15, 21–22, 29, 34–38, 42, 58–59, 

65–66, 70, 75, 117, 125, 127, 151, 156, 216–217, 

222, 250, 254, 256, 293, 296, 328, 364–365, 435, 

470 

client_locale environment variable 150 

CLOB 80, 178–180, 233, 276, 278, 450 

collection 10 

collection data type 145, 348 

collection variable 145 

commands 

esql 14, 125–128, 130 

commit work 140 

committed read 448 

compiler 130 

complex data type 335 

component object model 216 

concentrator 5 

concurrency 438 

concurrent query 19 

concurrent session 5 

connection management 192 

connection object 171 

connection pooling 155 

connection string 257 

connection string attribute 221 

connection_adapters directory 370 

connectionstring property 264 

constraint 190 

controller 363 

convention over configuration 384 

cost factor 333 

cost function 332 

cursor behavior 62 

cursor stability 447–448 


customer object 190 

customized routine 330 

D 

data access layer 190 

Data accessibility 143 

data consistency 8 

data consumer 14 

Data Definition Language (DDL) 134, 168, 198, 

294, 310, 391 

data logging 143 

data management 7 

Data Manipulation Language (DML) 198 

data mart 7 

data provider 14, 254 

data query language 190 

data source 155 

data source name 61 

data type extension 330 

data warehouse 7 

database driver 44 

database extension 330 

database instance name 449 

database locale 62 

database lock 442 

database operation 76 

datetime 80 

db_locale 63 

db_locale environment variable 150 

db2cli.ini 73 

db2jcc.jar 52, 194 

db2jcc4.jar 52 

db2sdriver.cfg configuration file 261 

DbDataReader method 269 

dbschema utility 395 

dbspace 450 

dbspacetemp parameter 450 

deadlock 446 

deadlock_timeout parameter 455 

def_table_lockmode parameter 441, 454 

delete 76 

dependency list 337 

directives parameter 456 

dirty read isolation 445 

discarded-logging 194 

display environment variable 38 

distinct 10, 80 

distinct data type 330, 335

distributed transaction 20, 93, 447, 470 

distributed transactions 154 

distribution statistic 333 

dmg format 26 

dom4j-1.6.1.jar 194 

DRDA protocol 156 

DRDADEBUG trace 188 

driver manager 11 

driver package 44 

drsoctcp 31 

dyld_library_path environment variable 131 

dynamic link library 350 

dynamic sql 136 

dynamic_logs configuration parameter 460 

E 

editions 2 

element type 145 

encryption 182 

end-user routine 332 

environment variable 

ld_library_path 131–132, 353, 365 

lib 132 

libpath 131 

shlib_path 131, 365 

esql command 14, 125–128, 130 

exception 206 

exclusive lock 439 

exclusive mode 438–439 

execute into command 134 

executeQuery() 168 

executeUpdate() 168 

export routine 333 

F 

fast data loading 7 

fetch buffer size 62 

filetoblob 144 

finderr utility 14, 37, 126 

flat file 9 

flow-control extension 331 

functional test file 16 

G 

gem utility 370 

generator element 201 

get diagnostics statement 149 

get() method 206 

GetIfxMonthSpan 270 

global transaction 470 

global transactions 447 

H 

header file 16, 471 

Hibernate dialect 196 

Hibernate service 195 

Hibernate session instance 203 

hibernate.cfg.xml 195 

hibernate.property 195 

hibernate3.jar 193 

hibernate-jpa-2.0-api-1.0.0.Final.jar 193 

HibernateUtil class 202 

high availability clustering 3 

high availability replication 19 

host name 61 

host variable 146 

HQL criteria 209 

HQL restriction 209 

HTTP link 422 

I 

i4gl_func 408 

IBM.Data.DB2 255 

IBM.Data.Informix 255 

ICommand interface 225 

idssecuritylabel 80 

ifx_lo_lock() 444 

ifx_lo_open 82 

ifx_lo_t 142 

ifx_lo_write 82 

IfxBlob GetIfxBlob() 265, 269 

IfxClob GetIfxClob() 265, 269 

IfxCommand 269 

IfxCommand class 266 

IfxCommand CreateCommand() 265 

IfxCommand method 272 

IfxConnection class 265 

IfxConnection object 274 

IfxDataReader 269 

IfxDataReader ExecuteReader() 266 

IfxDateTime class 283 

IfxDateTime GetIfxDateTime() 269 

IfxDateTime public method 284 

IfxDecimal GetIfxDecimal 269 

IfxDecimal object 287 

Index 483

IfxDecimal public method 287 

ifxdotnettrace variable 293 

IfxError 271 

IfxException class 271 

ifxjdbc.jar 194 

IfxMonthSpan 270 

ifxoledbc COM class ID 216 

ifxoledbctrace environment variable 248 

IfxParameter 273 

IfxParameter CreateParameter() 266 

IfxParameterCollection object 272 

IfxTimeSpan GetIfxTimeSpan 270 

IfxTransaction 265 

IfxTransaction object 274 

iifxoledbc.dll 216 

iLogin utility 37, 117, 126, 217, 290 

Implict invocation 334 

incoming parameter 337 

Informix classes 12 

Informix Client Software Development Kit , see Client 

SDK 

Informix Connect 9, 34–35, 328 

Informix OLE DB Provider 37 

informixc.so 365 

informixdir environment variable 21, 59, 127 

informixserver 353 

informixserver environment variable 133, 365 

informix-sqli 164 

inheritance 190 

insert 76 

installation directory 21 

installation ini file 27 

installIDSDriver command 44 

int8 80 

intent locks 439 

intent-exclusive lock 439 

intent-shared 439 

interval day 80 

interval day to hour 81 

interval day to minute 81 

interval day to second 81 

interval hour 81 

interval hour to minute 81 

interval hour to second 81 

interval minute 81 

interval minute to second 81 

interval month 81 

interval second 81 

interval year 81 


interval year to month 81 

Isolation Level 62, 70 

isolation level 20, 438, 447, 463 

ISupportErrorInfo interface 234 

Iterator function 332 

J 

Java annotation 191 

Java archive file 341 

Java class file 195 

Java compiler 195 

Java interface 12 

Java library 193, 195 

Java Naming and Directory Interface 166 

java property 195 

Java runtime 166 

Java virtual machine (JVM) 37, 157, 195, 340, 457 

java_bindir environment variable 341 

java_home environment variable 341 

java_root environment variable 341 

java.io.Serializable 12 

java.lang.object 13 

java.sql.ParameterMetaData 12 

javassist-3.9.0.GA.jar 194 

javax.sql extensions 163 

javax.sql.ConnectionEventListener 12 

javax.sql.ConnectionPoolDataSource 12 

javax.sql.DataSource 12 

javax.sql.PooledConnection 12 

javax.sql.XADataSource 12 

JDBC API interfaces 155 

JDBC class 155 

JDBC method 155 

JDBC standard 8 

jjdk_home environment variable 341 

JNDI, see Java Naming and Directory Interface. 

jre_home environment variable 341 

jta-1.1.jar 194 

JVM 37, 157, 195, 340, 457 

jvp.log 347 

K 

key 441 

Key lock 442 

keystore file 183 

key-value locking 442

L 

library file 126 

licensing metric 5 

limited use socket 5 

list 145 

load() 206 

load() method 206 

loc_t 142 

lock 438 

lock duration 440 

lock list 446 

lock mode page 441 

locks parameter 453 

logbuff 458 

logfiles parameter 458 

logging mode 463 

logical device 8 

logical volume manager 8 

logical-log buffer 20, 458 

logical-log record 20 

long identifier 10 

loopback connection 8 

LPAR 5 

ltxehwm parameter 460 

ltxhwm parameter 460 

LU socket 6 

lvarchar 81 

M 

make file 16 

mapping 191 

max_pdqpriority parameter 456 

MaxBytes 277 

memory addressability 2 

messages files 16 

method 190 

method properties 

position 277 

ReferenceCount 277 

mi_lo_lock() 444 

migration 394 

model 363 

module 16 

money 81 

msgpath file 347 

multimedia capability 8 

multiplexed connection 18–19 

multiplexer 5 

multiprocessor parameter 452 

multiset 145 

mutexes 18 

mutually exclusive 18 

N 

native-protocol 53 

nchar 81 

negator function 332 

nettype parameter 453 

network connection 18 

nvarchar 81 

O 

obdcinst.ini file 66 

object ExecuteScalar() 266 

object file 126 

object processing 191 

object-orientated programming 190 

object-relational mapper 363 

ODBC data source 60 

ODBC driver 59 

ODBC driver configuration files 

odbc 66 

odbcinst.ini 66 

sqlhosts 66 

ODBC libraries 

libifcli.a or libcli.a 66 

libifcli.so or iclis09b.so 66 

libifdrm.so or idmrs09a.so 66 

libthcli.a 66 

libthcli.so or iclit09b.so 66 

odbc.ini file 66 

ODBC/CLI driver 45 

OLE DB consumer 216 

OLE DB provider 216 

OLE DB providers 

DBTYPE_DBDATE 223 

DBTYPE_DBTIME 223 

DBTYPE_DBTIMESTAMP 224 

olsoctcp 31 

onconfig file 341 

onconfig parameter 

dbservername 449 

jvpclasspath 341 

jvphome 341 

jvpjavahome 341 

jvpjavalib 341 

Index 485

jvpjavavm 341 

jvplog 347 

jvplogfile 341 

jvppropfile 341 

oninit 18 

opaque 10 

opaque data type 330, 332, 335 

OpenAdmin Tool (OAT) 9, 17, 295, 297–299 

operator 333 

operator function 332 

operator-class function 332 

optcompind parameter 19, 455 

OUT parameter 173 

outgoing parameter 337 

P 

packaging file 16 

page level lock 441 

page locking 442 

parallel subquery 19 

parallelism 19 

parallelizable UDR 332 

parsing 139 

partition 5 

path environment variable 127 

path variable 59 

persistence 191, 363 

persistence data 190 

persistence framework 190 

persistence object 199 

persistent connectivity layer 5 

phantom read 448 

physbuff configuration parameter 458 

physical log image 20 

physical-log buffer 458 

pipe connection 18 

placeholder 88, 308 

Plain Old Java Objects (POJO) 199 

POJO, see Plain Old Java Object (POJO). 

polymorphism 190 

precedence hierarchy 337 

prepare statement 20 

prepared statement 175 

PreparedStatement object 169 

preprocessor 10 

primary key 201 

priority aging 462 

process memory 347 


processor affinity 462 

processor value unit 5 

processor-based pricing 5 

program_design_dbs 404 

Project Object Model (POM) 194 

public method 265 

publish 402 

pure-Java driver 53 

pure-Java drivers 154 

Q 

query optimization 139 

query plan 334 

query-intensive analytical application 7 

R 

rails command 392 

recovery 330 

Redbooks Web site 480 

Contact us xiv 

regsvr32 tool 245 

repeatable read 438, 448 

resource manager 470 

result set 173 

rollback 21, 330, 447 

rollback method 274 

rollback work statement 140 

row and collection functions 

ifx_rc_count 106 

ifx_rc_create 106 

ifx_rc_delete 106 

ifx_rc_describe 106 

ifx_rc_fetch 106 

ifx_rc_free 106 

ifx_rc_insert 106 

ifx_rc_isnull 106 

ifx_rc_setnull 106 

ifx_rc_typespec 106 

ifx_rc_update 106 

rowset 229 

R-tree 358 

Ruby/Informix Adapter 384 

S 

sbspacename parameter 451 

sbspacetemp parameter 451 

scaffold command 393

scalability 6, 330 

scalable data warehousing 7 

sdk_home environment variable 341 

secure sockets layer 19 

secured connection method 19 

select 76 

selectivity function 332 

serial8 81 

server definition 31 

server instance 18 

server name 61 

server_locale environment variable 150 

service-oriented architecture 400 

Session.createCiteria() 206 

Session.createQuery() 206 

Session.delete() method 210 

Session.get() 205 

Session.load() 205 

Session.save() 205 

SessionFactory class 202 

set 145 

set isolation 438 

set lock mode 438 

set transaction 438 

setnet32.exe utility 21, 29–31, 42, 61, 66, 117, 126, 

222, 245, 247, 449 

shared library 67 

shared lock 439 

shared memory 18, 20 

simple large objects 314 

Simple Logging Facade for Java (SLF4J) 194–195 

simple-logging 194 

single install 5 

single password CSM 19 

single-user product version 8 

SLF4J see Simple Logging Facade for Java. 

slf4j-api-1.5.8.jar 194 

slob method 377 

smart blob space 95, 143, 178 

smart lager objects 179 

smart large object 10 

smart large object functions 

ifx_lo_alter 97 

ifx_lo_close 97 

ifx_lo_col_info 97 

ifx_lo_create 97 

ifx_lo_def_create_spec 97 

ifx_lo_open 97 

ifx_lo_read 97 

ifx_lo_readwithseek 97 

ifx_lo_seek 97 

ifx_lo_specget_estbytes 97 

ifx_lo_specget_extsz 97 

ifx_lo_specget_flags 97 

ifx_lo_specget_maxbytes 97 

ifx_lo_specget_sbspace 97 

ifx_lo_specset_estbytes 97 

ifx_lo_specset_extsz 97 

ifx_lo_specset_flags 97 

ifx_lo_specset_maxbytes 97 

ifx_lo_specset_sbspace 98 

ifx_lo_stat 98 

ifx_lo_stat_atime 98 

ifx_lo_stat_cspec 98 

ifx_lo_stat_ctime 98 

ifx_lo_stat_refcnt 98 

ifx_lo_stat_size 98 

ifx_lo_tell 98 

ifx_lo_truncate 98 

ifx_lo_write 98 

ifx_lo_writewithseek 98 

smart large objects 178–180, 182, 232, 276, 278, 

280–281, 315, 377, 383 

soa_err_log log file 404 

SOAP 422 

socket connection 18 

source file 126 

source files 16 

SQL communications area 148 

SQL dialect 196 

SQL optimization 197 

sql_autocommit_off 91 

sql_bigint 80–81 

sql_bit 80 

sql_c_binary 80 

sql_ifmx_udt_blob 80 

sql_ifmx_udt_clob 80 

sql_infx_attr_lo_automatic 104 

sql_infx_bigint 80 

sql_infx_udt_fixed 80–81 

sql_infx_udt_varying 81 

sql_integer 81 

sql_interval_day 80 

sql_interval_hour 81 

sql_interval_month 81 

sql_interval_second 81 

sql_interval_year 81 

sql_longbinary 104 

Index 487

sql_longvarbinary 80, 96 

sql_longvarchar 81, 96, 104 

sql_timestamp 80 

sqlca 148 

sqlexec 30 

SQLExecDirect() 82 

SQLExecDirect() function 82 

SQLGetDiagRec() 84 

sqlhosts file 21, 27–29, 33–34, 42, 66, 127, 157, 

365, 449, 453 

sqlidebug trace 119, 151 

sqliprt tool 120 

sqlj.zip 52 

sqlj4.zip 52 

SQLSetConnectAttr() 91 

SQLSTATE 149 

stacksize parameter 454 

standard data type 330 

startup cost 337 

Statement object 168 

static SQL statement 136 

statistics function 332 

stored procedure 133 

structured query language 154 

subscribe 402 

sysdistrib system catalog table 451 

syslangauth table 331 

syspgm4gl 406 

sysprocauth table 331 

sysprocbody table 331 

sysprocedures table 331 

sysroutinelangs table 331 

syssbspacename parameter 451 

system catalog table 331 

T 

table space 450 

tar file 26 

target_dir 408 

target_file 408 

temporary space 450 

temporary table 450 

text export routine 333 

text import routine 333 

Text input routine 333 

text output routine 333 

third-party vendor 11 

thread 439 


TimeSpan GetTimeSpan() 269 

transaction 470 

transaction control 330 

transaction management 192 

transient 210 

transient object 210 

translation library 62 

translation option 62 

Type 4 154 

type constructor 145 

U 

UDR 173, 330–332, 334, 336–337, 340, 343, 345, 

347–348, 352, 451 

UDRManager 13 

UDRMetaData 13 

UDTManager 13 

UDTMetaData 13 

uncommitted data 448 

unit of work 470 

unresolved transaction 475 

updatable lock 439 

update 76 

uselastcommitted 441, 454 

user thread 464 

user-defined aggregate 332 

user-defined data type 335 

user-defined routine , see UDR. 

utilities 

finderr 14, 37, 126 

setnet32.exe 21, 29–31, 42, 61, 66, 117, 126, 

222, 245, 247, 449 

V 

validity checking 139 

version numbering convention 2 

virtual processor 18 

virtual server 5 

virtual-processor process 352 

VMB character 62 

void Prepare() 266 

vpclass parameter 452, 461 

W 

w4glc parameters 

check 405 

compile 405

deploy 405 

force 405 

generate 405 

help 405 

keep 405 

package 405 

silent 405 

version 405 

web server 363 

web service description language 407 

web service function 426 

workload 3 

ws_func 408 

WSDL Path 426 

wsdl_path 407 

X 

xa.h 471 

XML configuration file 190 

XML formatted file 195 

XML mapping file 197 

XML-based protocol 422 

Index 489


(1.0” spine) 

0.875”1.498” 

460 788 pages 

IBM Informix Developer’s Handbook


Developer’s Handbook 

Learn application 

development with 

supported APIs, 

drivers, and interfaces 

Understand Informix 

supported 

programming 

environments 

Follow practical 

examples to develop 

an Informix 

application 

SG24-7884-00 ISBN 0738434701 

Back cover 

IBM Informix is a low-administration, easy-to-use, and embeddable 

database that is ideal for application development. It supports a 

wide range of development platforms, such as Java, .NET, PHP, and 

web services, enabling developers to build database applications in 

the language of their choice. Informix is designed to handle RDBMS 

data and XML without modification and can be extended easily to 

handle new data sets. 

This IBM Redbooks publication provides fundamentals of Informix 

application development. It covers the Informix Client installation 

and configuration for application development environments. It 

discusses the skills and techniques for building Informix 

applications with Java, ESQL/C, OLE DB, .NET, PHP, Ruby on Rails, 

DataBlade, and Hibernate. 

The book uses code examples to demonstrate how to develop an 

Informix application with various drivers, APIs, and interfaces. It 

also provides application development troubleshooting and 

considerations for performance. 

This book is intended for developers who use IBM Informix for 

application development. Although some of the topics that we 

discuss are highly technical, the information in the book might also 

be helpful for managers or database administrators who are 

looking to better understand their Informix development 

environment. 

INTERNATIONAL 

TECHNICAL 

SUPPORT 

ORGANIZATION 

® 

BUILDING TECHNICAL 

INFORMATION BASED ON 

PRACTICAL EXPERIENCE 

IBM Redbooks are developed by 

the IBM International Technical 

Support Organization. Experts 

from IBM, Customers and 

Partners from around the world 

create timely technical 

information based on realistic 

scenarios. Specific 

recommendations are provided 

to help you implement IT 

solutions more effectively in 

your environment. 

For more information: 


®

IBM Informix Developer's Handbook - IBM Redbooks

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?