I have 3 objects, that are like this

Entity
Business : Entity
Individual : Entity

Business and Individual are inherited from Entity
I want a return type of Entity (Which will be a mix of Business and Individuals).
I can't seem to set criteria on the subclasses (Business or Entity) in HQL.

Is it possible?

I tried something like this :

select entity from Entity entity, Individual i, Business b
where i.FirstName like ......

but returned way too many results and was extrememly slow.

I should add that an entity can ONLY be a Business or Individual
and if primary key of Business is 56 then the primary key of entity is also 56
Any suggestions?

what strategy for mapping the inheritance do you use?
usually "from ent Entity where ...." should return also derived objects (if your inheritance mapping strategy supports that)

Cheers,
Radu

Yes, I can do a search with no criteria and get back Entities (which are actually of type Individual and Business). I can set criteria on the Entity but it can only relate to the entity class (which works as expected), but is not what i want. Basically it all works great without criteria.

Problem is i need to set criteria on the Individual object but return Entity objects.

At the moment it looks like i have to resort to running two queries, one to return Individuals (setting the criteria), and one query to run the Businesses (also setting criteria)

This seems to be a big problem for me.
How does HQL support inheritence and criteria on the subclass.

The entity can be a business or a individual

Entity
Business : Entity
Individual : Entity

The Entity plays one or many roles, one being a Client ( a bag)

Client inherits from Role
(Client : Role)

The client then has applications from there. (bag)

Say I took my original problem and decided to return Businesses instead of Entities. I can set criteria ok on the Businesses however i need to be able to search all Clients that match this role that the entity is playing, and then search the associated applications.




Ive done a lot of reading, and searching, to no prevail. (equivalient of Hibernate 2.1 i believe).


It is a comples scenario but posts like this from Gavin on the HIBERNATE forum do not sound promising : (referring to 2.1)

"HQL never, ever supported navigating through a collection-valued association! I find it very difficult to believe that this ever worked, but if it did, it worked by accident in some small number of cases and was never part of the official definition of HQL as per the documentation."


can someone confirm if what i am attempting can be done please??

Well, I'm using polymorphic collections myself and they are working.
Post details of your mappings, class definitions and queries you want to perform.

cheers,
radu