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Difference between revisions of "EclipseLink/UserGuide/JPA/Basic JPA Development/Entities/Ids/Generating and Configuring Entity Identities"
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*[[EclipseLink/UserGuide/JPA/Basic JPA Development/Mapping/Entity/IdClass|@IdClass]] | *[[EclipseLink/UserGuide/JPA/Basic JPA Development/Mapping/Entity/IdClass|@IdClass]] | ||
*[[EclipseLink/UserGuide/JPA/Basic JPA Development/Mapping/Entity/EmbeddedId|@EmbeddedId]] | *[[EclipseLink/UserGuide/JPA/Basic JPA Development/Mapping/Entity/EmbeddedId|@EmbeddedId]] | ||
| − | * @GeneratedValue | + | *[[EclipseLink/UserGuide/JPA/Basic JPA Development/Mapping/Entity/GeneratedValue|@GeneratedValue]] |
* @TableGenerator | * @TableGenerator | ||
* @SequenceGenerator | * @SequenceGenerator | ||
Revision as of 12:21, 17 June 2010
Entity
Every entity must have a persistent identity, which is an equivalent of a primary key in a database table that stores the entity state.
By default, the EclipseLink persistence provider assumes that each entity has at least one field or property that serves as a primary key.
You can generate and/or configure the identity of your entities by using the following annotations:
- @Id
- @IdClass
- @EmbeddedId
- @GeneratedValue
- @TableGenerator
- @SequenceGenerator
You can also use these annotations to fine-tune how your database maintains the identity of your entities.
 Mapping |
@Id |
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