Enterprise bean deployment tool schema

Here are the options for mapping entity beans to a back end database schema:

• Top-down
  With the top-down option, the deployment tools generate a back end schema directly from the provided abstract persistence schema (abstract accessor methods plus the deployment descriptor elements) and then map the elements in the abstract persistence schema to the generated back end schema. See the Generating a top-down mapping topic in the WebSphere Studio Application Developer (WSAD) documentation for details.

• Meet-in-the-middle
  With meet-in-the-middle mapping, you employ a tool to manually map elements from the abstract persistence schema to elements in an existing back end schema. WSAD provides a meet-in-the-middle mapping tool. See the Generating a meet-in-the-middle mapping topic in the WSAD documentation for details.

• Bottom-up
  With the bottom-up approach, the tools take, as input, an existing back end database schema and generate equivalent entity beans and then map the elements of the two schemas. See the Generating a bottom-up mapping topic in the WSAD documentation for details.