Task overview: Accessing data from applications

Why and when to perform this task

Various enterprise information systems (EIS) use different methods for storing data. These backend data stores might be relational databases, procedural transaction programs, or object-oriented databases. IBM WebSphere Application Server provides several options for accessing an information system's backend data store:

Programming directly to the database through the JDBC 2.0 optional package API or the JDBC 3.0 API.
Programming to the procedural backend transaction through various J2EE Connector Architecture (JCA) 1.0 or 1.5 compliant connectors.
Programming in the bean-managed persistence (BMP) bean or servlets indirectly accessing the backend store through either the JDBC API or JCA compliant connectors.
Using container-managed persistence (CMP) beans.
Using embedded Structured Query Language in Java (SQLJ) support with applications that use DB2 as a backend database.
Using the IBM data access beans, which also use the JDBC API, but give you a rich set of features and function that hide much of the complexity associated with accessing relational databases.

For all of these options, except for using the JCA 1.0 or 1.5 compliant connectors, the prerequisite Web site details which databases and drivers are currently supported. Consult the IBM Web address: http://www.ibm.com/software/webservers/appserv/doc/latest/prereq.html .

Develop data access applications. Develop your application to access data using the various ways available through the WebSphere Application Server. You can access data through APIs, container-managed persistence beans, bean-managed persistence beans, session beans, or Web components.
Assemble data access applications using the assembly tool. Assemble your application by creating and mapping resource references.
Prepare for deployment: Ensure that the appropriate database objects are available. Create or configure any databases or tables required, set necessary configuration parameters to handle expected load, and configure any necessary JDBC providers and data source objects for servlets, enterprise beans, and client applications to use.
Install the application on your application server.

Sub-topics
Resource adapter
Connection factory
JDBC providers
Data sources
Data access beans
Connection management architecture
Cache instances
Developing data access applications
Assembling data access applications using the assembly tool
Deploying data access applications
Administering data access applications
Data access: Resources for learning

Related tasks
Installing application files

Related reference
J2C Administered Objects collection