I have one-to-many relationship defined in my Set object.



and the composite key on the SetPoint object



When I do a search for a Set hibernate generates a query to find a Set and then one query for each point - very inneficient.

When I change my composite key to this



And add many-to-one relationship



It works as expected. One query to find Set and one to find all the points for the Set, but the problem is when I'm adding new Point to Set and want to persist it because I have pointId and Point objects in my PointSet hibernate is saying that this two are different.

I think first approach is how it should be implemented, but is there a way to force a join so it does only a single select for all the points rather than one for each point.

Thanks

Try this



This should force an outer join fetch if you want this as your default behaviour.

Otherwise, depending on how you can actually fetching your data, HQL or CriteriaAPI you can tell it how you would want that collection fetched.

The problem is with many-to-one relationship not one-to-many so I would have to add fetch="join" inside my composite key:



which as far as I know.. I can't.

Hibernate generates many SQL queries to get a Point for each Point Set, and this is were the problem is.

Thanks

You don't need it in your composite key, it's the Set that is driving the fetch of the PointSet bag.