I have the following situation in my schema:

There is a User table. Users can belong to just one Group. There is no need for navigating from Groups to Users. These two tables are related by a third table: UserGroup. In this third table, the FK column from User is the PK.

Is it possible to _naturally_ - no association class or many to many - map this relationship with Hibernate? If not, what would be the not-that-ugly approach? In case it's not possible, can someone please tell me where should i look for in the sources in order to implement this feature?

Tnx,
Michael

Hi,
Your db design seems to indicate that it is not 1:1, so why would you try to use 1:1 in your object model?

Sounds like using many-many would be the way to go.

James

Not really. USER_ID is the PK in UserGroup. So, a User belongs to zero or one Group in this case. I don't need to navigate this relationship from Group to User, but there are other cases in this database in which there are truly one-to-one relationships - like, in table AB one key is the PK from table A and the one from table B is an AK. I'd like to know the best way to map this situation with Hibernate.

There is no support for one-to-one across an association table. You will have to look at mapping to the associate table and possible hide these details behind some service methods.