Hi Christian,
thank you for your answer. I’d like to use inheritance of embeddables just
in the second scenario, i. e. A extends B and the entity property is of type
A.
I experienced that EclipseLink does not map the superclass attributes unless
B ist annotated @MappedSuperclass. Hibernate and openJPA seem to map
superclass attributes without any special annotation. AFIK relates the spec
@MappedSuperclass to entity classes only. Is it legal to use it on
embeddables? Is EclipLink spec-conform?
Thanks and regards
Dirk
Von: Christian von Kutzleben [mailto:cvkutzleben_at_versant.com]
Gesendet: Dienstag, 25. Juni 2013 09:59
An: users_at_jpa-spec.java.net
Betreff: [jpa-spec users] Re: Embeddable and inheritance
Hi Dirk,
It depends, what you want to achieve:
JPA targets relational databases and embedded objects don't have
an identity on their own and are supposed to be mapped to the owners table
(single refs), or
the respective tables to be joined to the owners row (col/maps refs).
So polymorphism does not work, if this is, what you wanted to do, then the
answer would be "no".
If you don't plan to use polymorphism and only derive them for convenience,
then the answer would be "yes",
as an Embeddable class adheres to the same rules like an Entity (except
marked as embeddable rather then entity)
Regards,
Christian
On Mon, Jun 24, 2013 at 11:26 PM, <dirk.weil_at_gedoplan.de> wrote:
Do embeddables allow inheritance, i. e. may an embeddable be derived
from some other embeddable?
Thanks
Dirk
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