| This annotation specifies a primary key column that is used
as a foreign key to join to another table.
It is used to join the primary table of an entity subclass
in the
InheritanceType.JOINED JOINED mapping strategy
to the primary table of its superclass; it is used within a
SecondaryTable annotation to join a secondary table
to a primary table; and it may be used in a
OneToOne
mapping in which the primary key of the referencing entity
is used as a foreign key to the referenced entity.
If no PrimaryKeyJoinColumn annotation is
specified for a subclass in the
InheritanceType.JOINED JOINED mapping strategy, the foreign key columns are assumed
to have the same names as the primary key columns of the
primary table of the superclass
Example: Customer and ValuedCustomer subclass
@Entity
@Table(name="CUST")
@Inheritance(strategy=JOINED)
@DiscriminatorValue("CUST")
public class Customer { ... }
@Entity
@Table(name="VCUST")
@DiscriminatorValue("VCUST")
@PrimaryKeyJoinColumn(name="CUST_ID")
public class ValuedCustomer extends Customer { ... }
since:
Java Persistence 1.0 |