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Made the caching of related and reverse related objects consistent in…

… OneToOneFields. Fixed #13839. Refs #17439.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17890 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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commit b90d4e5b749be3b6caec8ece7729beb3876ea4b8 1 parent 1f11069
@aaugustin aaugustin authored
View
55 django/db/models/fields/related.py
@@ -249,11 +249,19 @@ def __get__(self, instance, instance_type=None):
if instance is None:
return self
try:
- return getattr(instance, self.cache_name)
+ rel_obj = getattr(instance, self.cache_name)
except AttributeError:
params = {'%s__pk' % self.related.field.name: instance._get_pk_val()}
- rel_obj = self.get_query_set(instance=instance).get(**params)
+ try:
+ rel_obj = self.get_query_set(instance=instance).get(**params)
+ except self.related.model.DoesNotExist:
+ rel_obj = None
+ else:
+ setattr(rel_obj, self.related.field.get_cache_name(), instance)
setattr(instance, self.cache_name, rel_obj)
+ if rel_obj is None:
+ raise self.related.model.DoesNotExist
+ else:
return rel_obj
def __set__(self, instance, value):
@@ -331,24 +339,27 @@ def get_prefetch_query_set(self, instances):
def __get__(self, instance, instance_type=None):
if instance is None:
return self
-
try:
- return getattr(instance, self.cache_name)
+ rel_obj = getattr(instance, self.cache_name)
except AttributeError:
val = getattr(instance, self.field.attname)
if val is None:
- # If NULL is an allowed value, return it.
- if self.field.null:
- return None
- raise self.field.rel.to.DoesNotExist
- other_field = self.field.rel.get_related_field()
- if other_field.rel:
- params = {'%s__pk' % self.field.rel.field_name: val}
+ rel_obj = None
else:
- params = {'%s__exact' % self.field.rel.field_name: val}
- qs = self.get_query_set(instance=instance)
- rel_obj = qs.get(**params)
+ other_field = self.field.rel.get_related_field()
+ if other_field.rel:
+ params = {'%s__pk' % self.field.rel.field_name: val}
+ else:
+ params = {'%s__exact' % self.field.rel.field_name: val}
+ qs = self.get_query_set(instance=instance)
+ # Assuming the database enforces foreign keys, this won't fail.
+ rel_obj = qs.get(**params)
+ if not self.field.rel.multiple:
+ setattr(rel_obj, self.field.related.get_cache_name(), instance)
setattr(instance, self.cache_name, rel_obj)
+ if rel_obj is None and not self.field.null:
+ raise self.field.rel.to.DoesNotExist
+ else:
return rel_obj
def __set__(self, instance, value):
@@ -385,17 +396,13 @@ def __set__(self, instance, value):
# populated the cache, then we don't care - we're only accessing
# the object to invalidate the accessor cache, so there's no
# need to populate the cache just to expire it again.
- related = getattr(instance, self.field.get_cache_name(), None)
+ related = getattr(instance, self.cache_name, None)
# If we've got an old related object, we need to clear out its
# cache. This cache also might not exist if the related object
# hasn't been accessed yet.
- if related:
- cache_name = self.field.related.get_cache_name()
- try:
- delattr(related, cache_name)
- except AttributeError:
- pass
+ if related is not None:
+ setattr(related, self.field.related.get_cache_name(), None)
# Set the value of the related field
try:
@@ -405,9 +412,11 @@ def __set__(self, instance, value):
setattr(instance, self.field.attname, val)
# Since we already know what the related object is, seed the related
- # object cache now, too. This avoids another db hit if you get the
+ # object caches now, too. This avoids another db hit if you get the
# object you just set.
- setattr(instance, self.field.get_cache_name(), value)
+ setattr(instance, self.cache_name, value)
+ if value is not None and not self.field.rel.multiple:
+ setattr(value, self.field.related.get_cache_name(), instance)
class ForeignRelatedObjectsDescriptor(object):
# This class provides the functionality that makes the related-object
View
70 tests/regressiontests/one_to_one_regress/tests.py
@@ -132,3 +132,73 @@ def test_filter_one_to_one_relations(self):
Target.objects.exclude(pointer2=None),
[]
)
+
+ def test_reverse_object_does_not_exist_cache(self):
+ """
+ Regression for #13839 and #17439.
+
+ DoesNotExist on a reverse one-to-one relation is cached.
+ """
+ p = Place(name='Zombie Cats', address='Not sure')
+ p.save()
+ with self.assertNumQueries(1):
+ with self.assertRaises(Restaurant.DoesNotExist):
+ p.restaurant
+ with self.assertNumQueries(0):
+ with self.assertRaises(Restaurant.DoesNotExist):
+ p.restaurant
+
+ def test_reverse_object_cached_when_related_is_accessed(self):
+ """
+ Regression for #13839 and #17439.
+
+ The target of a one-to-one relation is cached
+ when the origin is accessed through the reverse relation.
+ """
+ # Use a fresh object without caches
+ r = Restaurant.objects.get(pk=self.r1.pk)
+ p = r.place
+ with self.assertNumQueries(0):
+ self.assertEqual(p.restaurant, r)
+
+ def test_related_object_cached_when_reverse_is_accessed(self):
+ """
+ Regression for #13839 and #17439.
+
+ The origin of a one-to-one relation is cached
+ when the target is accessed through the reverse relation.
+ """
+ # Use a fresh object without caches
+ p = Place.objects.get(pk=self.p1.pk)
+ r = p.restaurant
+ with self.assertNumQueries(0):
+ self.assertEqual(r.place, p)
+
+ def test_reverse_object_cached_when_related_is_set(self):
+ """
+ Regression for #13839 and #17439.
+
+ The target of a one-to-one relation is always cached.
+ """
+ p = Place(name='Zombie Cats', address='Not sure')
+ p.save()
+ self.r1.place = p
+ self.r1.save()
+ with self.assertNumQueries(0):
+ self.assertEqual(p.restaurant, self.r1)
+
+ def test_reverse_object_cached_when_related_is_unset(self):
+ """
+ Regression for #13839 and #17439.
+
+ The target of a one-to-one relation is always cached.
+ """
+ b = UndergroundBar(place=self.p1, serves_cocktails=True)
+ b.save()
+ with self.assertNumQueries(0):
+ self.assertEqual(self.p1.undergroundbar, b)
+ b.place = None
+ b.save()
+ with self.assertNumQueries(0):
+ with self.assertRaises(UndergroundBar.DoesNotExist):
+ self.p1.undergroundbar
View
30 tests/regressiontests/select_related_onetoone/tests.py
@@ -79,4 +79,32 @@ def test_nullable_relation(self):
p1 = Product.objects.create(name="Django Plushie", image=im)
p2 = Product.objects.create(name="Talking Django Plushie")
- self.assertEqual(len(Product.objects.select_related("image")), 2)
+ with self.assertNumQueries(1):
+ result = sorted(Product.objects.select_related("image"), key=lambda x: x.name)
+ self.assertEqual([p.name for p in result], ["Django Plushie", "Talking Django Plushie"])
+
+ self.assertEqual(p1.image, im)
+ # Check for ticket #13839
+ self.assertIsNone(p2.image)
+
+ def test_missing_reverse(self):
+ """
+ Ticket #13839: select_related() should NOT cache None
+ for missing objects on a reverse 1-1 relation.
+ """
+ with self.assertNumQueries(1):
+ user = User.objects.select_related('userprofile').get(username='bob')
+ with self.assertRaises(UserProfile.DoesNotExist):
+ user.userprofile
+
+ def test_nullable_missing_reverse(self):
+ """
+ Ticket #13839: select_related() should NOT cache None
+ for missing objects on a reverse 0-1 relation.
+ """
+ Image.objects.create(name="imag1")
+
+ with self.assertNumQueries(1):
+ image = Image.objects.select_related('product').get()
+ with self.assertRaises(Product.DoesNotExist):
+ image.product
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