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from django.db import models, IntegrityError
from django.test import TestCase, skipUnlessDBFeature, skipIfDBFeature
from modeltests.delete.models import (R, RChild, S, T, U, A, M, MR, MRNull,
create_a, get_default_r, User, Avatar, HiddenUser, HiddenUserProfile)
class OnDeleteTests(TestCase):
def setUp(self):
self.DEFAULT = get_default_r()
def test_auto(self):
a = create_a('auto')
a.auto.delete()
self.assertFalse(A.objects.filter(name='auto').exists())
def test_auto_nullable(self):
a = create_a('auto_nullable')
a.auto_nullable.delete()
self.assertFalse(A.objects.filter(name='auto_nullable').exists())
def test_setvalue(self):
a = create_a('setvalue')
a.setvalue.delete()
a = A.objects.get(pk=a.pk)
self.assertEqual(self.DEFAULT, a.setvalue)
def test_setnull(self):
a = create_a('setnull')
a.setnull.delete()
a = A.objects.get(pk=a.pk)
self.assertEqual(None, a.setnull)
def test_setdefault(self):
a = create_a('setdefault')
a.setdefault.delete()
a = A.objects.get(pk=a.pk)
self.assertEqual(self.DEFAULT, a.setdefault)
def test_setdefault_none(self):
a = create_a('setdefault_none')
a.setdefault_none.delete()
a = A.objects.get(pk=a.pk)
self.assertEqual(None, a.setdefault_none)
def test_cascade(self):
a = create_a('cascade')
a.cascade.delete()
self.assertFalse(A.objects.filter(name='cascade').exists())
def test_cascade_nullable(self):
a = create_a('cascade_nullable')
a.cascade_nullable.delete()
self.assertFalse(A.objects.filter(name='cascade_nullable').exists())
def test_protect(self):
a = create_a('protect')
self.assertRaises(IntegrityError, a.protect.delete)
def test_do_nothing(self):
# Testing DO_NOTHING is a bit harder: It would raise IntegrityError for a normal model,
# so we connect to pre_delete and set the fk to a known value.
replacement_r = R.objects.create()
def check_do_nothing(sender, **kwargs):
obj = kwargs['instance']
obj.donothing_set.update(donothing=replacement_r)
models.signals.pre_delete.connect(check_do_nothing)
a = create_a('do_nothing')
a.donothing.delete()
a = A.objects.get(pk=a.pk)
self.assertEqual(replacement_r, a.donothing)
models.signals.pre_delete.disconnect(check_do_nothing)
def test_inheritance_cascade_up(self):
child = RChild.objects.create()
child.delete()
self.assertFalse(R.objects.filter(pk=child.pk).exists())
def test_inheritance_cascade_down(self):
child = RChild.objects.create()
parent = child.r_ptr
parent.delete()
self.assertFalse(RChild.objects.filter(pk=child.pk).exists())
def test_cascade_from_child(self):
a = create_a('child')
a.child.delete()
self.assertFalse(A.objects.filter(name='child').exists())
self.assertFalse(R.objects.filter(pk=a.child_id).exists())
def test_cascade_from_parent(self):
a = create_a('child')
R.objects.get(pk=a.child_id).delete()
self.assertFalse(A.objects.filter(name='child').exists())
self.assertFalse(RChild.objects.filter(pk=a.child_id).exists())
def test_setnull_from_child(self):
a = create_a('child_setnull')
a.child_setnull.delete()
self.assertFalse(R.objects.filter(pk=a.child_setnull_id).exists())
a = A.objects.get(pk=a.pk)
self.assertEqual(None, a.child_setnull)
def test_setnull_from_parent(self):
a = create_a('child_setnull')
R.objects.get(pk=a.child_setnull_id).delete()
self.assertFalse(RChild.objects.filter(pk=a.child_setnull_id).exists())
a = A.objects.get(pk=a.pk)
self.assertEqual(None, a.child_setnull)
def test_o2o_setnull(self):
a = create_a('o2o_setnull')
a.o2o_setnull.delete()
a = A.objects.get(pk=a.pk)
self.assertEqual(None, a.o2o_setnull)
class DeletionTests(TestCase):
def test_m2m(self):
m = M.objects.create()
r = R.objects.create()
MR.objects.create(m=m, r=r)
r.delete()
self.assertFalse(MR.objects.exists())
r = R.objects.create()
MR.objects.create(m=m, r=r)
m.delete()
self.assertFalse(MR.objects.exists())
m = M.objects.create()
r = R.objects.create()
m.m2m.add(r)
r.delete()
through = M._meta.get_field('m2m').rel.through
self.assertFalse(through.objects.exists())
r = R.objects.create()
m.m2m.add(r)
m.delete()
self.assertFalse(through.objects.exists())
m = M.objects.create()
r = R.objects.create()
MRNull.objects.create(m=m, r=r)
r.delete()
self.assertFalse(not MRNull.objects.exists())
self.assertFalse(m.m2m_through_null.exists())
def test_bulk(self):
from django.db.models.sql.constants import GET_ITERATOR_CHUNK_SIZE
s = S.objects.create(r=R.objects.create())
for i in xrange(2*GET_ITERATOR_CHUNK_SIZE):
T.objects.create(s=s)
# 1 (select related `T` instances)
# + 1 (select related `U` instances)
# + 2 (delete `T` instances in batches)
# + 1 (delete `s`)
self.assertNumQueries(5, s.delete)
self.assertFalse(S.objects.exists())
def test_instance_update(self):
deleted = []
related_setnull_sets = []
def pre_delete(sender, **kwargs):
obj = kwargs['instance']
deleted.append(obj)
if isinstance(obj, R):
related_setnull_sets.append(list(a.pk for a in obj.setnull_set.all()))
models.signals.pre_delete.connect(pre_delete)
a = create_a('update_setnull')
a.setnull.delete()
a = create_a('update_cascade')
a.cascade.delete()
for obj in deleted:
self.assertEqual(None, obj.pk)
for pk_list in related_setnull_sets:
for a in A.objects.filter(id__in=pk_list):
self.assertEqual(None, a.setnull)
models.signals.pre_delete.disconnect(pre_delete)
def test_deletion_order(self):
pre_delete_order = []
post_delete_order = []
def log_post_delete(sender, **kwargs):
pre_delete_order.append((sender, kwargs['instance'].pk))
def log_pre_delete(sender, **kwargs):
post_delete_order.append((sender, kwargs['instance'].pk))
models.signals.post_delete.connect(log_post_delete)
models.signals.pre_delete.connect(log_pre_delete)
r = R.objects.create(pk=1)
s1 = S.objects.create(pk=1, r=r)
s2 = S.objects.create(pk=2, r=r)
t1 = T.objects.create(pk=1, s=s1)
t2 = T.objects.create(pk=2, s=s2)
r.delete()
self.assertEqual(
pre_delete_order, [(T, 2), (T, 1), (S, 2), (S, 1), (R, 1)]
)
self.assertEqual(
post_delete_order, [(T, 1), (T, 2), (S, 1), (S, 2), (R, 1)]
)
models.signals.post_delete.disconnect(log_post_delete)
models.signals.post_delete.disconnect(log_pre_delete)
@skipUnlessDBFeature("can_defer_constraint_checks")
def test_can_defer_constraint_checks(self):
u = User.objects.create(
avatar=Avatar.objects.create()
)
a = Avatar.objects.get(pk=u.avatar_id)
# 1 query to find the users for the avatar.
# 1 query to delete the user
# 1 query to delete the avatar
# The important thing is that when we can defer constraint checks there
# is no need to do an UPDATE on User.avatar to null it out.
self.assertNumQueries(3, a.delete)
self.assertFalse(User.objects.exists())
self.assertFalse(Avatar.objects.exists())
@skipIfDBFeature("can_defer_constraint_checks")
def test_cannot_defer_constraint_checks(self):
u = User.objects.create(
avatar=Avatar.objects.create()
)
a = Avatar.objects.get(pk=u.avatar_id)
# 1 query to find the users for the avatar.
# 1 query to delete the user
# 1 query to null out user.avatar, because we can't defer the constraint
# 1 query to delete the avatar
self.assertNumQueries(4, a.delete)
self.assertFalse(User.objects.exists())
self.assertFalse(Avatar.objects.exists())
def test_hidden_related(self):
r = R.objects.create()
h = HiddenUser.objects.create(r=r)
p = HiddenUserProfile.objects.create(user=h)
r.delete()
self.assertEqual(HiddenUserProfile.objects.count(), 0)
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