object.some_set.all().delete() does not call the delete method on some object

[gert@…]

If you override an objects delete method:

object.something_set.all().delete()

does not do the same as:

for something in object.something_set.all():
    something.delete()

The new delete method is never called and hence any associated cleanup or audit code are never called. This comes to light when you delete an object which in turn deletes related objects.

[Johannes Dollinger]

#7360 might be a duplicate.

How should this be implemented? (​http://groups.google.at/group/django-developers/browse_thread/thread/8807069717e78370)

[Malcolm Tredinnick]

This is only open until I (or somebody else) writes a documentation patch. The delete() method is primarily a mass-SQL operation, just like update(). However, because I suspect we sometimes do call delete() on some of the auxilliary objects, I'd like to try and document when that happens in case somebody does write a custom method. Really, though, there shouldn't be many custom delete() methods. Performing secondary actions for a delete is better done via post-delete signal handlers. Calling the delete() method on every object that has one will just slow things down.

So the resolution here is a docs patch, nothing more.

[James Bennett]

(In [8406]) Fixed #6915: Documented the fact that QuerySet.delete() may not call delete() methods of individual objects

[Jacob]

Milestone 1.0 deleted