Question

I have the following problem. I have three classes, A, B and C. A contains a OneToMany relationed list of B:s. B contains a ManyToOne relation to C. C contains a field called “name” and B also contains a field called “name”. What I’d like to accomplish is to have the items in A’s list sorted primarily by C’s name and secondarily by B’s name – the problem is that I do not know how to do this. Is it even possible?

I’m using EclipseLink as my JPA provider.

class A {
   @OneToMany
   @OrderBy("b.c.name, b.name") <---- this is the problem
   List<B> b;
}

class B {
   @ManyToOne
   C c;
   String name;
}

class C {
   String name;
}

EDIT
Yes, I’ve tried different variations, for example @OrderBy(“c.name”) doesn’t work, I just get an error message telling me that the entity class b does not contain a field called “c.name”.

Answer 1

It’s NOT possible. @OrderBy only accepts direct property / field names, not nested properties. Which makes sense, really, because “c” table – depending on your fetching strategy may not even be part of a select issued to retrieve your “b”s.