Working with Java Object Relationship Mappings

Relational mappings define how persistent objects reference other persistent objects. TopLink furnishes the following relationship mappings:

One-to-one mappings - Map a reference to another persistent Java object to the database (see "Working with One-to-One Mappings" ).
One-to-many mappings - Map Java collections of persistent objects to the database (see "Working with One-to-Many Mappings" ).
Many-to-many mappings - Use an association table to map Java collections of persistent objects to the database (see "Working with Many-to-Many Mappings" ).
Direct collection mappings - Map Java collections of objects that do not have descriptors (see "Working with Direct Collection Mappings" ).
Aggregate object mappings - Strict one-to-one mappings that require both objects to exist in the same database row (see "Working with Aggregate Mappings" ).
Aggregate collection mappings - Map Java collections of persistent objects to the database (see "Working with Aggregate Collection Mappings" ).
Variable one-to-one mappings - Map a reference to an interface to the database (see "Working with Variable One-to-One Mappings" ).