Why and when to perform this task
You can map enterprise bean JAR files (EJB modules) to relational database (RDB) tables using the EJB to RDB Mapping wizard of the Assembly Toolkit. The wizard creates EJB to RDB mappings for the following situations:Top-down and meet-in-the-middle mapping support multiple backends, making multiple deployments inside a single EJB module configurable at run time. Bottom-up mapping only supports a single backend. A backend can represent different database vendors, or simply alternative mappings and table qualifiers. If multiple backends exist, then current BackendID needs to be set in the EJB deployment descriptor editor (when working with EJB 2.0 beans). This mapping is used at run time when the JAR is installed on WebSphere Application Server. When deploying EJB 1.1 beans inside an EJB 2.0 project, the EJB 1.1 beans are deployed only once, using the first declared database and type. You specify a Backend ID in an EJB deployment descriptor editor under WebSphere Bindings. The Backend ID determines the persister classes that get loaded at deployment.
Steps for this task