(Optional) The name of the persistent field or property of the associated entity that is used as the map key.
Default: If the name element is not specified, the primary key of the associated entity is used as the map key. If the primary key is a composite primary key and is mapped as IdClass, an instance of the primary key class is used as the key.
- Default:
- ""
- Since:
- Jakarta Persistence (JPA) 1.0