Mapping refers to the ability to tie an object-based model to a relational model of data, usually the schema of a relational database. The CMP implementation provides the ability to tie a set of interrelated beans containing data and associated behaviors to the schema. This object representation of the database becomes part of the Java application. You can also customize this mapping to optimize these beans for the particular needs of an application. The result is a single data model through which both persistent database information and regular transient program data are accessed.
The mapping capabilities provided by the Application Server include:
Mapping a CMP bean to one or more tables
Mapping CMP fields to one or more columns
Mapping CMP fields to different column types
Mapping tables with compound primary keys
Mapping tables with unknown primary keys
Mapping CMP relationships to foreign keys
Mapping tables with overlapping primary and foreign keys