Inherited models are not fully deleted

[John Millikin]

With the following models:

class Place (models.Model):
	name = models.CharField (max_length = 255, unique = True)
	
class Store (Place):
	manager = models.CharField (max_length = 255)
	

This is the behavior of delete(), which is unexpected. Attempting to delete objects with inherited relationships leaves a trail of half-built objects behind. The call to store.delete() should also remove the associated Place.

>>> store = Store.objects.create (name = "My Store", manager = "Frank")
>>> store.id
1
>>> store.delete ()
>>> Place.objects.get (id = 1).name
'My Store'
>>> Store.objects.create (name = "My Store", manager = "Bob")
Traceback (most recent call last):
    ...
IntegrityError: (1062, "Duplicate entry 'My Store' for key 2")
>>> 

[John Millikin]

Updated model inheritance unit tests

[Julien Phalip]

There needs to be a design decision: do we want or not to delete the parent *automatically* when the child is deleted?

It is still possible to do it manually with something like:

class Store (Place):

parent = models.OneToOneField(Place, parent_link=True)
manager = models.CharField (max_length = 255)

def delete(self):

parent.delete()

[Malcolm Tredinnick]

(In [7784]) Fixed #7276 -- Delete multi-table objects correctly.

When model inheritance is used, the parent objects should be deleted as part of
the delete() call on the child.

[Jacob]

Milestone 1.0 deleted