from operator import attrgetter from django.contrib.contenttypes.models import ContentType from django.contrib.sessions.backends.db import SessionStore from django.db import models from django.db.models import Count from django.test import TestCase, ignore_warnings, override_settings from django.utils.deprecation import RemovedInDjango50Warning from .models import ( Base, Child, Derived, Feature, Item, ItemAndSimpleItem, Leaf, Location, OneToOneItem, Proxy, ProxyRelated, RelatedItem, Request, ResolveThis, SimpleItem, SpecialFeature, ) class DeferRegressionTest(TestCase): def test_basic(self): # Deferred fields should really be deferred and not accidentally use # the field's default value just because they aren't passed to __init__ Item.objects.create(name="first", value=42) obj = Item.objects.only("name", "other_value").get(name="first") # Accessing "name" doesn't trigger a new database query. Accessing # "value" or "text" should. with self.assertNumQueries(0): self.assertEqual(obj.name, "first") self.assertEqual(obj.other_value, 0) with self.assertNumQueries(1): self.assertEqual(obj.value, 42) with self.assertNumQueries(1): self.assertEqual(obj.text, "xyzzy") with self.assertNumQueries(0): self.assertEqual(obj.text, "xyzzy") # Regression test for #10695. Make sure different instances don't # inadvertently share data in the deferred descriptor objects. i = Item.objects.create(name="no I'm first", value=37) items = Item.objects.only("value").order_by("-value") self.assertEqual(items[0].name, "first") self.assertEqual(items[1].name, "no I'm first") RelatedItem.objects.create(item=i) r = RelatedItem.objects.defer("item").get() self.assertEqual(r.item_id, i.id) self.assertEqual(r.item, i) # Some further checks for select_related() and inherited model # behavior (regression for #10710). c1 = Child.objects.create(name="c1", value=42) c2 = Child.objects.create(name="c2", value=37) Leaf.objects.create(name="l1", child=c1, second_child=c2) obj = Leaf.objects.only("name", "child").select_related()[0] self.assertEqual(obj.child.name, "c1") self.assertQuerySetEqual( Leaf.objects.select_related().only("child__name", "second_child__name"), [ "l1", ], attrgetter("name"), ) # Models instances with deferred fields should still return the same # content types as their non-deferred versions (bug #10738). ctype = ContentType.objects.get_for_model c1 = ctype(Item.objects.all()[0]) c2 = ctype(Item.objects.defer("name")[0]) c3 = ctype(Item.objects.only("name")[0]) self.assertTrue(c1 is c2 is c3) # Regression for #10733 - only() can be used on a model with two # foreign keys. results = Leaf.objects.only("name", "child", "second_child").select_related() self.assertEqual(results[0].child.name, "c1") self.assertEqual(results[0].second_child.name, "c2") results = Leaf.objects.only( "name", "child", "second_child", "child__name", "second_child__name" ).select_related() self.assertEqual(results[0].child.name, "c1") self.assertEqual(results[0].second_child.name, "c2") # Regression for #16409 - make sure defer() and only() work with annotate() self.assertIsInstance( list(SimpleItem.objects.annotate(Count("feature")).defer("name")), list ) self.assertIsInstance( list(SimpleItem.objects.annotate(Count("feature")).only("name")), list ) @ignore_warnings(category=RemovedInDjango50Warning) @override_settings( SESSION_SERIALIZER="django.contrib.sessions.serializers.PickleSerializer" ) def test_ticket_12163(self): # Test for #12163 - Pickling error saving session with unsaved model # instances. SESSION_KEY = "2b1189a188b44ad18c35e1baac6ceead" item = Item() item._deferred = False s = SessionStore(SESSION_KEY) s.clear() s["item"] = item s.save(must_create=True) s = SessionStore(SESSION_KEY) s.modified = True s.save() i2 = s["item"] self.assertFalse(i2._deferred) def test_ticket_16409(self): # Regression for #16409 - make sure defer() and only() work with annotate() self.assertIsInstance( list(SimpleItem.objects.annotate(Count("feature")).defer("name")), list ) self.assertIsInstance( list(SimpleItem.objects.annotate(Count("feature")).only("name")), list ) def test_ticket_23270(self): d = Derived.objects.create(text="foo", other_text="bar") with self.assertNumQueries(1): obj = Base.objects.select_related("derived").defer("text")[0] self.assertIsInstance(obj.derived, Derived) self.assertEqual("bar", obj.derived.other_text) self.assertNotIn("text", obj.__dict__) self.assertEqual(d.pk, obj.derived.base_ptr_id) def test_only_and_defer_usage_on_proxy_models(self): # Regression for #15790 - only() broken for proxy models proxy = Proxy.objects.create(name="proxy", value=42) msg = "QuerySet.only() return bogus results with proxy models" dp = Proxy.objects.only("other_value").get(pk=proxy.pk) self.assertEqual(dp.name, proxy.name, msg=msg) self.assertEqual(dp.value, proxy.value, msg=msg) # also test things with .defer() msg = "QuerySet.defer() return bogus results with proxy models" dp = Proxy.objects.defer("name", "text", "value").get(pk=proxy.pk) self.assertEqual(dp.name, proxy.name, msg=msg) self.assertEqual(dp.value, proxy.value, msg=msg) def test_resolve_columns(self): ResolveThis.objects.create(num=5.0, name="Foobar") qs = ResolveThis.objects.defer("num") self.assertEqual(1, qs.count()) self.assertEqual("Foobar", qs[0].name) def test_reverse_one_to_one_relations(self): # Refs #14694. Test reverse relations which are known unique (reverse # side has o2ofield or unique FK) - the o2o case item = Item.objects.create(name="first", value=42) o2o = OneToOneItem.objects.create(item=item, name="second") self.assertEqual(len(Item.objects.defer("one_to_one_item__name")), 1) self.assertEqual(len(Item.objects.select_related("one_to_one_item")), 1) self.assertEqual( len( Item.objects.select_related("one_to_one_item").defer( "one_to_one_item__name" ) ), 1, ) self.assertEqual( len(Item.objects.select_related("one_to_one_item").defer("value")), 1 ) # Make sure that `only()` doesn't break when we pass in a unique relation, # rather than a field on the relation. self.assertEqual(len(Item.objects.only("one_to_one_item")), 1) with self.assertNumQueries(1): i = Item.objects.select_related("one_to_one_item")[0] self.assertEqual(i.one_to_one_item.pk, o2o.pk) self.assertEqual(i.one_to_one_item.name, "second") with self.assertNumQueries(1): i = Item.objects.select_related("one_to_one_item").defer( "value", "one_to_one_item__name" )[0] self.assertEqual(i.one_to_one_item.pk, o2o.pk) self.assertEqual(i.name, "first") with self.assertNumQueries(1): self.assertEqual(i.one_to_one_item.name, "second") with self.assertNumQueries(1): self.assertEqual(i.value, 42) def test_defer_with_select_related(self): item1 = Item.objects.create(name="first", value=47) item2 = Item.objects.create(name="second", value=42) simple = SimpleItem.objects.create(name="simple", value="23") ItemAndSimpleItem.objects.create(item=item1, simple=simple) obj = ItemAndSimpleItem.objects.defer("item").select_related("simple").get() self.assertEqual(obj.item, item1) self.assertEqual(obj.item_id, item1.id) obj.item = item2 obj.save() obj = ItemAndSimpleItem.objects.defer("item").select_related("simple").get() self.assertEqual(obj.item, item2) self.assertEqual(obj.item_id, item2.id) def test_proxy_model_defer_with_select_related(self): # Regression for #22050 item = Item.objects.create(name="first", value=47) RelatedItem.objects.create(item=item) # Defer fields with only() obj = ProxyRelated.objects.select_related().only("item__name")[0] with self.assertNumQueries(0): self.assertEqual(obj.item.name, "first") with self.assertNumQueries(1): self.assertEqual(obj.item.value, 47) def test_only_with_select_related(self): # Test for #17485. item = SimpleItem.objects.create(name="first", value=47) feature = Feature.objects.create(item=item) SpecialFeature.objects.create(feature=feature) qs = Feature.objects.only("item__name").select_related("item") self.assertEqual(len(qs), 1) qs = SpecialFeature.objects.only("feature__item__name").select_related( "feature__item" ) self.assertEqual(len(qs), 1) def test_defer_annotate_select_related(self): location = Location.objects.create() Request.objects.create(location=location) self.assertIsInstance( list( Request.objects.annotate(Count("items")) .select_related("profile", "location") .only("profile", "location") ), list, ) self.assertIsInstance( list( Request.objects.annotate(Count("items")) .select_related("profile", "location") .only("profile__profile1", "location__location1") ), list, ) self.assertIsInstance( list( Request.objects.annotate(Count("items")) .select_related("profile", "location") .defer("request1", "request2", "request3", "request4") ), list, ) def test_common_model_different_mask(self): child = Child.objects.create(name="Child", value=42) second_child = Child.objects.create(name="Second", value=64) Leaf.objects.create(child=child, second_child=second_child) with self.assertNumQueries(1): leaf = ( Leaf.objects.select_related("child", "second_child") .defer("child__name", "second_child__value") .get() ) self.assertEqual(leaf.child, child) self.assertEqual(leaf.second_child, second_child) self.assertEqual(leaf.child.get_deferred_fields(), {"name"}) self.assertEqual(leaf.second_child.get_deferred_fields(), {"value"}) with self.assertNumQueries(0): self.assertEqual(leaf.child.value, 42) self.assertEqual(leaf.second_child.name, "Second") with self.assertNumQueries(1): self.assertEqual(leaf.child.name, "Child") with self.assertNumQueries(1): self.assertEqual(leaf.second_child.value, 64) class DeferDeletionSignalsTests(TestCase): senders = [Item, Proxy] @classmethod def setUpTestData(cls): cls.item_pk = Item.objects.create(value=1).pk def setUp(self): self.pre_delete_senders = [] self.post_delete_senders = [] for sender in self.senders: models.signals.pre_delete.connect(self.pre_delete_receiver, sender) models.signals.post_delete.connect(self.post_delete_receiver, sender) def tearDown(self): for sender in self.senders: models.signals.pre_delete.disconnect(self.pre_delete_receiver, sender) models.signals.post_delete.disconnect(self.post_delete_receiver, sender) def pre_delete_receiver(self, sender, **kwargs): self.pre_delete_senders.append(sender) def post_delete_receiver(self, sender, **kwargs): self.post_delete_senders.append(sender) def test_delete_defered_model(self): Item.objects.only("value").get(pk=self.item_pk).delete() self.assertEqual(self.pre_delete_senders, [Item]) self.assertEqual(self.post_delete_senders, [Item]) def test_delete_defered_proxy_model(self): Proxy.objects.only("value").get(pk=self.item_pk).delete() self.assertEqual(self.pre_delete_senders, [Proxy]) self.assertEqual(self.post_delete_senders, [Proxy])