Hibernate version: 3.0.5

Looking at the Hibernate 3 DTD here it appears that the many-to-one end of a bidirectional relationship does not support the inverse flag. This would seem to indicate that I can only set that flag on the collection side. Please clarify or point me to a clarification, a search on the forums and wiki did not turn up anything enlightening. All the example usage I have located has inverse on the collection side, but none mention that it may only be on that side.

While it's no longer strictly needed, finding this information would have helped me quite a bit several hours ago ;)

Thanks

inverse="true" means updates are done on the other side of the relationship.

If you have many-to-one association it means that the entity declaring the association say A has a reference to exactly one instance of the entity on the other side say B. While B has many instances of A refering to it. So it would not know what instance of A to update (especially if Many-To-One is unidirectional, which most of them are; think of Address (Many) - To - Country (One)).

In terms of DB tables it also makes no sense to have inverse attribute on many-to-one. If you have table A it will need b_id as FK to the PK of table B. So when you update/save an instance of A, you will not find a better way to update the b_id as to just update it on A's side.

HTH,
Alex.

Thanks for explaining that. In terms of inverse="true" on the many-to-one side I could imagine a system smart enough to know that in bidirectional relation A <>--<*B B1, B2, and B4 all need updating. I think I was also mixing up inverse and cascade, in terms of what does what when.

Anyway, thanks for the reply.