Module jakarta.persistence

Package jakarta.persistence

Annotation Interface MapsId

@Target({METHOD,FIELD})
@Retention(RUNTIME)
public @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 primary key of the entity 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:

2.0

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element	Description
String	value	(Optional) The name of the attribute within the composite key to which the relationship attribute corresponds.

Element Details

value

String value

(Optional) The name of the attribute within the composite key to which the relationship attribute corresponds. If not explicitly specified, the relationship maps the primary key of the entity.

Default:

""