Question

Lets supose that I have 3 abstract super classes: SuperA, SuperB and SuperC.
Lets supose that each of theses super classes had a lot of more specific implementations, and all the superclasses are annotated with @Inheritance(strategy = InheritanceType.JOINED).

More specific:

• Aa <- SuperA and has a List of SuperB (the bbs property);
• Bb <- SuperB and has a List of SuperC (the ccs property);
• Cc <- SuperC and has a foo property.

Then, when I try a query like the following, I got an error saying that it could not find the property foo in the type SuperC. Bb has a list of the abstract type, and I can’t change that. So, I do not know how to make the query works.

select a from Aa a left outer join a.bbs b where b.ccs.foo = :foo

Any tip will help. Thanks in advance.

---

Edit:

BTW: the exception:

org.hibernate.exception.SQLGrammarException: Unknown column 'cc3_1_.foo' in 'where clause'

---

Edit 2:

I look for JPA docs, and found something that could work, if I’m not using Hibernate.

---

Edit 3:

I change it to use two SQL’s. First, I find the id of the C based on the foo property, then I just do the query comparing with the id.

The problem here, is that I have to do 2 SQL’s for every time I want this… but, at least it works.

Answer 1

You need one more join for the list of Cc’s then it should be fine:

select a from Aa a left outer join a.bbs b join b.ccs c where c.foo = :foo

as ccs is a list you can’t “dereference” it’s property this way, if you could you wouldn’t need joins, you could simply write: a.bbs.ccs.foo but this is not the case so you need to join the lists as I wrote above.