Support for collections of embeddables and basic types
------------------------------------------------------
Key: OPENJPA-782
URL: https://issues.apache.org/jira/browse/OPENJPA-782
Project: OpenJPA
Issue Type: Question
Reporter: Fay Wang
Assignee: Fay Wang
Regarding jpa 2.0 embeddable, suppose Entity A contains a collection of
embeddables.
The collection of embeddable is stored in a separate table. @CollectionTable
can be used to specify the table name, etc. If the @CollectionTable is not
used, a default table name is used (see spec, p 272 ).
The embeddable may contain the relation to EntityB in the following scenarios:
(1) If in the embeddable, there is:
@ManyToOne
private EnittyB entityB;
then the relation from EntityA to EntityB is OneToMany,
and the relation from EntityB to EntityA is ManyToOne (Spec 2.5):
@ManyToOne
private EntityA entityA;
(2) If in the embeddable, there is:
@OneToOne
private EntityB;
then the relation from EntityA to EntityB is OneToMany,
and the relation from EntityB to EntityA is ManyToOne (Spec 2.5):
@ManyToOne
private EntityA entityA;
(3) If in the embeddable, there is:
@OneToOne(mappedBy = "entityB")
private EntityB
The relation from EntityA to EnityB is OneToMany,
and the relation from EntityB to EntityA is ManyToOne:
@ManyToOne
private EntityA entityA;
The relation to EntityB will be stored in the third table (the CollectionTable)
so that it can be associated with the embeddable. However, we can not use
"mappedBy" in the ManyToOne relation in EntityB. How to have bi-directional
relation between EntityA and EntityB in these situations? Is it possible to
have a bi-directional relation between these two entities when embeddable is
involved as described above?
In scenario (3), an explicit "mappedBy" is specified in the embeddable, so that
the bi-directional relation between EntityA and EntityB will be stored in the
EntityB table, but then how can we associate EntityB with the embeddable when
EntityA is retrieved back as embeddable itself does not have identity?
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
