I have 3 objects with relationships between each other. I'm deleting 2 of them, and I need the many-to-many relationship cleaned up. I want to simply remove it from the collection rather than deleting the owning object of the relationship. Here is my classes and relationships:


In this case I want to remove a Policy, and it needs to delete all of the PolicyVersion it owns. The above mapping will do just that. If I delete a Policy then all of the policy versions are deleted.

However, if I have a Job that references a PolicyVersion then if I try and delete the Policy object it fails with a constraint violation because PolicyVersion ID is stuck in a join table.

I tried to add a bi-directional reference in PolicyVersion to Job and set the relationship to CascadeType.REMOVE, but it doesn't every work. It's as if it ignores it. This new relationship is not the owning side of the relationship.

Can I cascade from the non-owning side of a relationship? Will the CascadeType.REMOVE actually remove it from the collection rather than deleting the Job? I want it just to remove the entry in the join table between Job and PolicyVersion (i.e. Job_PolicyVersion). I tried not setting the cascade and it still doesn't work.

If I have to use a delete statement (i.e. query) how to I say remove this thing from the collection and leave the Job instance?

Any ideas?

Charile

Well once again I figure it out on my own. But, I always like to contribute back to the forum in case someone else runs into this.

The answer is yes you can cascade both sides of the relationship. It doesn't matter that one side owns the relationship or not. The trick is I needed to do a refresh to associate the object with the session BEFORE deleting. So the answer was as simple as:



Why did refresh fix my problem? Well in my unit tests I wasn't maintaining the relationship between PolicyVersion and DeploymentJob in my code. Since I'm only mapping this relationship to cleanup the dependancies it doesn't have to maintained. But, this came back to bite me because if the relationship is null or empty hibernate thinks there's no DeploymentJob's with a relationship back to PolicyVersion. Hence nothing to delete.

Refresh initializes the PolicyVersion.jobs relationship and so Hibernate sees it as a delete.

Charlie