Question

We have a Listing entity and a ListingAddress entity in a one-to-many relationship. A ListingAddress shouldn’t exist without a Listing. I’d like any ListingAddress that is removed from a Listing’s addresses relationship to be deleted from the context. Is that possible, or do I have to do it by hand?

Answer 1

You have to do it by hand.

If the listing is deleted, it’s straightforward. See the Relationship Delete Rules. You can set it up to “Cascade” whereby the related object will be automatically deleted. You’ll still of course need tosaveany changes made to the context:

Cascade

Delete the objects at the destination of the relationship.
For example, if you delete a department, fire all the employees in that department at the same time.

But in your case, where the listing isn’t deleted, your orphaned ListingAddress objects have to be cleaned up manually. Here’s a couple of posts that cover that issue:

Deletions in a many-to-many structure

Core Data: re-setting to-many relationship