Develop data access applications

Various enterprise information systems use different methods for storing data. These back end data stores may be relational databases, procedural transaction programs, or object-oriented databases. WAS provides several options for accessing an information system's back end data store:

• Program directly to the database through the JDBC 2.0 Optional Package API.
• Program to the procedural back end transaction through various J2EE Connector Architecture (JCA) 1.0 compliant connectors.
• Program servlets or bean-managed persistence (BMP) enterprise bean to indirectly access the back end store through either the JDBC API or JCA compliant connectors.
• Use container-managed persistence (CMP) beans.
• Use IBM data access beans, which also use the JDBC API, but give you additional ability to manipulate result sets.

See these topics for information about developing data access applications, including code examples:

Data access development model
This topic discusses the general steps your code performs to access databases.

IBM extensions to the data access API
WAS provides extended data access APIs that you can use to access data.

Access data with J2EE Connector Architecture connectors
See this topic for information about programming your data access applications to the JCA specification.

Access connection pools from your components
This topic shows an example of how to write code that utilizes the WAS connection manager.

IBM data access JavaBeans
Another option you can use to access data is by using IBM's extension to the JavaBeans specification.

Data access exceptions
See this topic for information about handling exceptions in your data access applications with IBM extensions to data access exceptions.

Note: To utilize the connection management infrastructure in WAS V5, package your application as a J2EE 1.3 application. See Migrate a version 4.0 data access application to version 5.0 in the Migration topic for more information.