Here is a short desc of how our domain model looks like.

There is a unidirectional one-to-many mapping between A and B.

B has subclasses C and D

A has no knowledge of C and D. It is only aware of B by the mapping.

Abstract superclass B and its subclasses C and D are mapped via table per hierarchy.

C has a mapped property getPropertyFromC() for instance
D has a mapped property getPropertyFromD() for instance

How can I issue a query (via hql or criteria api) to find the list of A objects which have (C objects where PropertyFromC is ValueC) or (D objects where PropertyFromD is ValueD)

Seems like I need to do type casting or something in hql which is not possible.

Any suggestions ?

I don't know, if there's a more elegant solution, but I think that will work.





Now combine both ID lists to one list. Each ID must be unique since you are using table per class hierarchy.



Best regards
Sven

define getPropertyFromC and getPropertyFromD in B (override in C and D)

then do query :

from A a
where (a.discriminator='C' and b.propertyFromC='valueC')
or (a.discriminator='D' and b.propertyFromD='valueD')

regards

I'm sorry - this is correct
[/quote]

Yes, that's another solution, but it would be:


The discriminator is placed in B.
But that was probably a slip and it is just what you meant.

Best regards
Sven

Thanks for all the replies.
Is there a way to do this in one query only without using native sql?

The last one is one query and not native SQL. :)

But the problem with that is I will need to carry propertyC and propertyD to the abstract class where they will not make any sense except making the query work. Can do that as a workaround but looking for a permanent solution for such problems.