I have the classes City, Resort, Activity and Deal. Activity has two subclasses - CityActivity and ResortActivity - which each have a reference back to their respective City / Resort.

The classes are related like:

City many-many CityActivity
Resort 1-many ResortActivity
Activity many-many Deal

I want to create an HQL query that returns all the deals for a given resort, by joining "through" the activities table. I have:

select distinct d from Deal d join d.activities a join a.resort r where r.id = ?

but I can't use the "resort" attribute of the activity a in the above query, since all activities don't have a resort property. Only the ResortActivity has a resort property.

Do I have to split up my activities collection into two collections - one ResortActivities collection and one CityActivities collection - and then join to a.resortActivities?

This seems akward. I would be able to do the query in standard JDBC if I did something like:

select distinct d from deals d, deal_activities da, activities a where d.id = da.deal_id and da.activity_id = a.id and a.resort_id = ?

Thanks!

How about:



That should do what you want and return a list of tuples with the third element containing the Deals that you want.

If this doesn't work, which inheritance model are you using?

Please rate if this was helpful; I need the points to post.

You can try to add class specification so that only certain type of polymorph entity should be considered while joing activties to deals

That worked flawlessly - I think I was braindead when I made that post. How do I assign credits? I don't see a link for that option.

Found it - 1 credit to each of you.