Commit 3cbe7369 authored by Malcolm Tredinnick's avatar Malcolm Tredinnick
Browse files

Fixed #7778 -- Fixed a tricky case of foreign key clearing with inherited 

models. Patch from James Murty.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@8100 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent ccab4b04

AUTHORS

+1 −0
Original line number Diff line number Diff line
@@ -280,6 +280,7 @@ answer newbie questions, and generally made Django that much better: 
    Eric Moritz <http://eric.themoritzfamily.com/>

    mrmachine <real.human@mrmachine.net>

    Robin Munn <http://www.geekforgod.com/>

    James Murty

    msundstr

    Robert Myers <myer0052@gmail.com>

    Nebojša Dorđević

django/db/models/query.py

+3 −1
Original line number Diff line number Diff line
@@ -836,7 +836,9 @@ def delete_objects(seen_objs): 


        update_query = sql.UpdateQuery(cls, connection)

        for field in cls._meta.fields:

            if field.rel and field.null and field.rel.to in seen_objs:

            if (field.rel and field.null and field.rel.to in seen_objs and

                    filter(lambda f: f.column == field.column,

                    field.rel.to._meta.fields)):

                update_query.clear_related(field, pk_list)



    # Now delete the actual data.

tests/regressiontests/queries/models.py

+28 −0
Original line number Diff line number Diff line
@@ -190,6 +190,19 @@ class CustomPk(models.Model): 
class Related(models.Model):

    custom = models.ForeignKey(CustomPk)



# An inter-related setup with a model subclass that has a nullable

# path to another model, and a return path from that model.



class Celebrity(models.Model):

    name = models.CharField("Name", max_length=20)

    greatest_fan = models.ForeignKey("Fan", null=True, unique=True)



class TvChef(Celebrity):

    pass



class Fan(models.Model):

    fan_of = models.ForeignKey(Celebrity)





__test__ = {'API_TESTS':"""

>>> t1 = Tag.objects.create(name='t1')
@@ -836,6 +849,21 @@ related via ForeignKeys. 
>>> len(Note.objects.order_by('extrainfo__info').distinct())

3



Bug #7778 - Model subclasses could not be deleted if a nullable foreign key

relates to a model that relates back.



>>> num_celebs = Celebrity.objects.count()

>>> tvc = TvChef.objects.create(name="Huey")

>>> Celebrity.objects.count() == num_celebs + 1

True

>>> f1 = Fan.objects.create(fan_of=tvc)

>>> f2 = Fan.objects.create(fan_of=tvc)

>>> tvc.delete()



# The parent object should have been deleted as well.

>>> Celebrity.objects.count() == num_celebs

True



"""}



# In Python 2.3, exceptions raised in __len__ are swallowed (Python issue