Im wondering how best to implement certain delete operations in my application.
Ive got a Topic which has a set of Memberships to it. Each Membership is associated with a Subscriber. To complicate things, a Subscriber has its own association with Membership: It has the concept of a "default" Membership.

One of my use cases is to delete a Topic.
Im trying to thing about the best way to do this... I cant just "fire-and-forget" - Hibernate will arrange for the Memberships to be deleted but what about management of the Subscribers? (E.g, if we delete a default Membership, we need to update the Subscriber).
Triggers aren't an option (MySQL v4).

Should the service code just do this? I.e: Iterate over each membership in the Topic and update the Subscriber if necessary before the delete.
Or is this a good place for an interceptor?
Or is it my own fault for having a screwy model?

Many Thanks,

Dave

> Each Membership is associated with a Subscriber. To complicate things, a Subscriber has its own association with Membership: It has the concept of a "default" Membership.

to clarify, a Topic has this:



A Membership has this:



And a Subscriber has this:



So in my mapping I have a set of Memberships for a Topic.
I can set cascading deletes up so that when a Topic is deleted, the Memberships are also deleted.
But then if I delete a Topic, I might have Subscribers that point to deleted Memberships.

So currently, my service layer looks up the Topic and asks it to "clear()" itself. This, in turn, asks each membership is to clear() itself, which un-links itself from its subscriber (i.e: if subscriber.getDefaultMembership().equals(this), subscriber.setDefaultMembership(null) ).

Does this sound like a reasonable way to do it? It just feels a little "un-clean" to me.