IT. Expert System.

Java Enterprise Edition (EE)

EmbeddedId


javax.persistence
Annotation Type EmbeddedId

@Target(value={METHOD,FIELD})
@Retention(value=RUNTIME)
public @interface EmbeddedId

Applied to a persistent field or property of an entity class or mapped superclass to denote a composite primary key that is an embeddable class. The embeddable class must be annotated as Embeddable.

There must be only one EmbeddedId annotation and no Id annotation when the EmbeddedId annotation is used.

The AttributeOverride annotation may be used to override the column mappings declared within the embeddable class.

The MapsId annotation may be used in conjunction with the EmbeddedId annotation to specify a derived primary key.

If the entity has a derived primary key, the AttributeOverride annotation may only be used to override those attributes of the embedded id that do not correspond to the relationship to the parent entity.

Relationship mappings defined within an embedded id class are not supported.

    Example 1:

    @EmbeddedId
    protected EmployeePK empPK;


    Example 2:

    @Embeddable
    public class DependentId {
       String name;
       EmployeeId empPK;   // corresponds to primary key type of Employee
    }

    @Entity
    public class Dependent {
       // default column name for "name" attribute is overridden
       @AttributeOverride(name="name", @Column(name="dep_name"))
       @EmbeddedId DependentId id;
       ...
       @MapsId("empPK")
       @ManyToOne Employee emp;
    }
 

Since:
Java Persistence 1.0
See Also:
Embeddable, MapsId



Content

Android Reference

Java basics

Java Enterprise Edition (EE)

Java Standard Edition (SE)

SQL

HTML

PHP

CSS

Java Script

MYSQL

JQUERY

VBS

REGEX

C

C++

C#

Design patterns

RFC (standard status)

RFC (proposed standard status)

RFC (draft standard status)

RFC (informational status)

RFC (experimental status)

RFC (best current practice status)

RFC (historic status)

RFC (unknown status)

IT dictionary

License.
All information of this service is derived from the free sources and is provided solely in the form of quotations. This service provides information and interfaces solely for the familiarization (not ownership) and under the "as is" condition.
Copyright 2016 © ELTASK.COM. All rights reserved.
Site is optimized for mobile devices.
Downloads: 3555 / . Delta: 0.01029 с