Package javax.persistence
Annotation Interface MapsId
Designates a
ManyToOne
or
OneToOne
relationship attribute that provides the
mapping for an EmbeddedId
primary key, an attribute within
an EmbeddedId
primary key, or a simple primary key of
the parent entity. The value
element specifies the
attribute within a composite key to which the relationship
attribute corresponds. If the entity's primary key is of the same
Java type as the primary key of the entity referenced by the
relationship, the value attribute is not specified.
Example: // parent entity has simple primary key @Entity public class Employee { @Id long empId; String name; ... } // dependent entity uses EmbeddedId for composite key @Embeddable public class DependentId { String name; long empid; // corresponds to primary key type of Employee } @Entity public class Dependent { @EmbeddedId DependentId id; ... @MapsId("empid") // maps the empid attribute of embedded id @ManyToOne Employee emp; }
- Since:
- Java Persistence 2.0
-
Optional Element Summary
-
Element Details
-
value
String value(Optional) The name of the attribute within the composite key to which the relationship attribute corresponds. If not supplied, the relationship maps the entity's primary key.- Default:
- ""
-