Hibernate Inheritance Queries (Criteria)

Question

I have the following two classes (Java Hibernate):

public class Grupo{
          //plain Attributes
}

and

public class Salon extends Grupo{
          //plain Attributes
}

having objects of both types.

using the following Criteria Query:

s.createCriteria(Grupo.class).list();

I get all the Grupo-type objects, that is Grupo and Salon, as expected. So, what I want to know is that if there is a way in Criteria Query to easily get only the "Grupo" objects that are not "Salon" objects. I will like to refrain of using discriminators if possible (in db both classes have their own tables)

Any help will be highly appreciated.

EDIT: Corrected wrong java syntax, how lame of me.

Answer 1

The conceptual problem is that all Salon objects are Grupos.

Could you change Salon so that it doesn't derive from Grupo and instead Grupo and Salon share a base class?

Otherwise, you'll have to use discriminators.

Answer 2

If you don't have to use Criteria then you can do this with hql

s.createQuery("select g from Grupo g where g.class = Grupo").list();

As far as I know, with Criteria you must have a discriminator column for this to work.

s.createCriteria(Grupo.class).add(Restrictions.eq("class", "G").list();

if your discriminator value for Grupos is G.

The shared base class approach suggested by @Mark Robinson is also worth considering...