hql on subclass property

Question

I have a class A and sub-classes B and C which have different properties. How can I do something like: a from A a where ( a.class = B and a.specific-property-of-b = "y") or (a.class = C and a.specific-property-of-c ="z")

Is it possible to get hibernate understand that when it's an instance of a certain class then it can access the specific properties of it or is it impossible to do something like that and I have to do:

a from A a where a.id in (select b.id from B b where b.specific-property-of-b = "y") or a.id in (select c.id from C c where c.specific-property-of-c = "z")

Thank you

Answer 1

You do it as you suggested:

select a from A a 
where (a.class = B and a.specificPropertyOfB = 'y')
or (a.class = C and a.specificPropertyOfC = 'z')

The only thing that won't work correctly (in my experience) is if you define two persistent fields with the same name in both subclasses.