Hibernate NamedQuery with a condition on inner List

Question

    class A{
// one to many mapping
    List<B> listOfB;
    //getter and setter;
    class B {
    String s;
    //getter and setter
    }

Now, when I get class A , it will return all the associated class Bs in listOfB. But I need certain condition on which of B should be in response. Like Get A such that listOfB contains all such B for which s = 'something'.

EDIT : currently this is not working:

select a from A a where a.listOfB IN (select b from a.listOfB b where b.s='something');

Answer 1

1) I assume that you mapped a one-to-many relation from A to B like A.listOfB = Bb

I think your query can be simplified as:

select a 
from A a, B b
where a.listOfB = b.b
and where b.s='something'

The equivalent Hibernate Criteria query would be:

List results =  sess.createCriteria(A.class)  
    .createCriteria("listOfB")
    .add(Restrictions.eq("s", "something"))
    .list();

2) If there is no relation mapped between these entities you can use an SQLRestriction over the field a.listOfB

List results = sess.createCriteria(A.class)
.add( Restrictions.sqlRestriction("{alias}.listOfB in (selec b from B where b.s = ?)), "something", Hibernate.STRING) )
   .list();

More examples here .

Answer 2

You can do that with Hibernate, although the JPA spec says it should be forbidden. Indeed, when you get an A , its list of Bs should always be the complete list a Bs. Not a list that has been filtered by some query. I would avoid doing that because its dangerous. Rather, I would use a query like the following:

select a, b from A a inner join a.listOfB b where b.s = 'something'

Now you have all the As you're interested into, and all the Bs you're interested into:

A1, B1
A1, B2
A2, B7
A2, B8

If you really want to get As with partial list of Bs, use the following query. But you've been warned: it's not portable, and it's dangerous:

select a from A a inner join fetch a.listOfB b where b.s = 'something'