When you have foreign-key relationships between database tables, you usually want to preserve those relationships in the CMP beans mapped to those tables. Container-managed relationships (CMR) determine how relationships between mapped CMP beans are stored in the database. CMRs enable navigation from one bean to another, in the same way that a foreign key enables navigation from one table to another.
If you are deploying to the Sun Java System Application Server, you can configure CMRs in the Sun Configuration editor. If you are deploying to a different application server, you have to configure CMRs yourself in the server-specific deployment descriptors.
To edit your relationship field mappings:
In the Field Mappings table in the IDE, persistent fields with mapped relationships are indicated by <mapped relationship> in the Mapped Column column. When you create or modify field mappings in the Sun Configuration editor, the IDE makes these changes in the sun-cmp-mappings.xml file. The modified sun-cmp-mappings.xml file is copied to the Sun Java System Application Server when the application is deployed.