My model has two class hierarchies:
A2 extends A1
A3 extends A2
and
B2 extends B1
B3 extends B2

There is a relation from A1 to B1 named "b",
Set<B1> b;
in A1

I would like to do queries involving both sub classes of A1 and B1.

When doing queries using the org.hibernate.criterion package, I can do

Criteria c = DetachedCriteria.forEntityName(A1.class)
to create a root criteria, and then join with the other class using
c.createCriteria("b")
to create a nested criteria. This is all very good.

When creating the initial criteria,
DetachedCriteria.forEntityName(A1.class)
gives my all instances of sub classes of A1 (including A1).
DetachedCriteria.forEntityName(A2.class)
would give my all A2's and A3's, but not A1's.
This is also very good.

So to my question.
How do I specify the same for the B's, a restriction on the B1 class hierarchy?
The
Criteria.createCriteria(String associationPath)
do not take any entity type arguments. What I would like is
Criteria.createCriteria(String associationPath, Class entityType)

Say that I would like to have
all A2-s (including A3-s) and the related B2-s (including B3-s)

How do I do this using the org.hibernate.criterion package?
I know that hibernate uses a database column named dtype to discriminate subclasses in the same table,
and I could use this for add some kind of an sql criterion with information about the B1-B2-B3 classes.
But this gets really ugly, as then I will have to use a hard-coded representation of the class hierarchies
in the code, and I would also depend on hibernate not changing the name of the dtype column.

Can someone please help me. This should be basic functionality in a OR-mapping tool.


Regards
Øyvind Jergan

So to my question.
How do I specify the same for the B's, a restriction on the B1 class hierarchy?
The
Criteria.createCriteria(String associationPath)
do not take any entity type arguments. What I would like is
Criteria.createCriteria(String associationPath, Class entityType)


In your example you should be able to create a Criteria for A then:

criteria.createCriteria(associationPath).add(Criterion) where Criterion is an Example of you B and your association path would be the field name of B in A.

Thanks

Yes, that sounds correct.
So my question is then really, how do I create a Criterion that matches
"All instances of class B2 (and its sub classes including B2), but no instances of B which is not sub class of B2 (for example B1)"
?

Øyvind