I'm in the process of rewriting some legacy JDBC into hibernate, but am struggling with how to convert a given query. Or more to the point, I'm struggling with 'Is it a good idea to convert said query'.

The query joins 2 tables A and B via a 3rd table C. It returns the distinct values of a column from A and a column from B.

select distinct A.col, B.col
from A, B, C
where A.id = C.A_id
and B.id = C.B_ID

Clearly, I could brute force this modelling A, B, and C (A having a Set of C's, B having a set of C's, etc.), getting a list of A and walking on down. This seems rather heavy handed though. Not to mention, it turns a somewhat elegant SQL query into some hideously blunt code.

Surely there's a way to move a straightforward SQL join into Hibernate in some fashion.

A many-to-many to B

like in :
unidirectional many-to-many association

or :

bidirectional many-to-many association

And Chapter 14 explains quit a lot about HQL...

You can than do something like:



Hibernate will resolve for you through the mapping how to get from A to B

Good Luck!

What if you created a view and then mapped to that through hibernate?

I have never done it but as far as I know this is no problem