from __future__ import unicode_literals from django.test import TestCase from django.utils import six from .models import ( A, B, Building, C, Chick, Child, Class, Client, ClientStatus, Connection, Country, Device, Enrollment, Hen, Item, Organizer, Person, Port, SpecialClient, State, Student, TUser, ) class SelectRelatedRegressTests(TestCase): def test_regression_7110(self): """ Regression test for bug #7110. When using select_related(), we must query the Device and Building tables using two different aliases (each) in order to differentiate the start and end Connection fields. The net result is that both the "connections = ..." queries here should give the same results without pulling in more than the absolute minimum number of tables (history has shown that it's easy to make a mistake in the implementation and include some unnecessary bonus joins). """ b = Building.objects.create(name='101') dev1 = Device.objects.create(name="router", building=b) dev2 = Device.objects.create(name="switch", building=b) dev3 = Device.objects.create(name="server", building=b) port1 = Port.objects.create(port_number='4', device=dev1) port2 = Port.objects.create(port_number='7', device=dev2) port3 = Port.objects.create(port_number='1', device=dev3) c1 = Connection.objects.create(start=port1, end=port2) c2 = Connection.objects.create(start=port2, end=port3) connections = Connection.objects.filter(start__device__building=b, end__device__building=b).order_by('id') self.assertEqual( [(c.id, six.text_type(c.start), six.text_type(c.end)) for c in connections], [(c1.id, 'router/4', 'switch/7'), (c2.id, 'switch/7', 'server/1')] ) connections = ( Connection.objects .filter(start__device__building=b, end__device__building=b) .select_related() .order_by('id') ) self.assertEqual( [(c.id, six.text_type(c.start), six.text_type(c.end)) for c in connections], [(c1.id, 'router/4', 'switch/7'), (c2.id, 'switch/7', 'server/1')] ) # This final query should only have seven tables (port, device and building # twice each, plus connection once). Thus, 6 joins plus the FROM table. self.assertEqual(str(connections.query).count(" JOIN "), 6) def test_regression_8106(self): """ Regression test for bug #8106. Same sort of problem as the previous test, but this time there are more extra tables to pull in as part of the select_related() and some of them could potentially clash (so need to be kept separate). """ us = TUser.objects.create(name="std") usp = Person.objects.create(user=us) uo = TUser.objects.create(name="org") uop = Person.objects.create(user=uo) s = Student.objects.create(person=usp) o = Organizer.objects.create(person=uop) c = Class.objects.create(org=o) Enrollment.objects.create(std=s, cls=c) e_related = Enrollment.objects.all().select_related()[0] self.assertEqual(e_related.std.person.user.name, "std") self.assertEqual(e_related.cls.org.person.user.name, "org") def test_regression_8036(self): """ Regression test for bug #8036 the first related model in the tests below ("state") is empty and we try to select the more remotely related state__country. The regression here was not skipping the empty column results for country before getting status. """ Country.objects.create(name='Australia') active = ClientStatus.objects.create(name='active') client = Client.objects.create(name='client', status=active) self.assertEqual(client.status, active) self.assertEqual(Client.objects.select_related()[0].status, active) self.assertEqual(Client.objects.select_related('state')[0].status, active) self.assertEqual(Client.objects.select_related('state', 'status')[0].status, active) self.assertEqual(Client.objects.select_related('state__country')[0].status, active) self.assertEqual(Client.objects.select_related('state__country', 'status')[0].status, active) self.assertEqual(Client.objects.select_related('status')[0].status, active) def test_multi_table_inheritance(self): """ Exercising select_related() with multi-table model inheritance. """ c1 = Child.objects.create(name="child1", value=42) Item.objects.create(name="item1", child=c1) Item.objects.create(name="item2") self.assertQuerysetEqual( Item.objects.select_related("child").order_by("name"), ["", ""] ) def test_regression_12851(self): """ Regression for #12851 Deferred fields are used correctly if you select_related a subset of fields. """ australia = Country.objects.create(name='Australia') active = ClientStatus.objects.create(name='active') wa = State.objects.create(name="Western Australia", country=australia) Client.objects.create(name='Brian Burke', state=wa, status=active) burke = Client.objects.select_related('state').defer('state__name').get(name='Brian Burke') self.assertEqual(burke.name, 'Brian Burke') self.assertEqual(burke.state.name, 'Western Australia') # Still works if we're dealing with an inherited class SpecialClient.objects.create(name='Troy Buswell', state=wa, status=active, value=42) troy = SpecialClient.objects.select_related('state').defer('state__name').get(name='Troy Buswell') self.assertEqual(troy.name, 'Troy Buswell') self.assertEqual(troy.value, 42) self.assertEqual(troy.state.name, 'Western Australia') # Still works if we defer an attribute on the inherited class troy = SpecialClient.objects.select_related('state').defer('value', 'state__name').get(name='Troy Buswell') self.assertEqual(troy.name, 'Troy Buswell') self.assertEqual(troy.value, 42) self.assertEqual(troy.state.name, 'Western Australia') # Also works if you use only, rather than defer troy = SpecialClient.objects.select_related('state').only('name', 'state').get(name='Troy Buswell') self.assertEqual(troy.name, 'Troy Buswell') self.assertEqual(troy.value, 42) self.assertEqual(troy.state.name, 'Western Australia') def test_null_join_promotion(self): australia = Country.objects.create(name='Australia') active = ClientStatus.objects.create(name='active') wa = State.objects.create(name="Western Australia", country=australia) bob = Client.objects.create(name='Bob', status=active) jack = Client.objects.create(name='Jack', status=active, state=wa) qs = Client.objects.filter(state=wa).select_related('state') with self.assertNumQueries(1): self.assertEqual(list(qs), [jack]) self.assertEqual(qs[0].state, wa) # The select_related join wasn't promoted as there was already an # existing (even if trimmed) inner join to state. self.assertNotIn('LEFT OUTER', str(qs.query)) qs = Client.objects.select_related('state').order_by('name') with self.assertNumQueries(1): self.assertEqual(list(qs), [bob, jack]) self.assertIs(qs[0].state, None) self.assertEqual(qs[1].state, wa) # The select_related join was promoted as there is already an # existing join. self.assertIn('LEFT OUTER', str(qs.query)) def test_regression_19870(self): hen = Hen.objects.create(name='Hen') Chick.objects.create(name='Chick', mother=hen) self.assertEqual(Chick.objects.all()[0].mother.name, 'Hen') self.assertEqual(Chick.objects.select_related()[0].mother.name, 'Hen') def test_regression_10733(self): a = A.objects.create(name='a', lots_of_text='lots_of_text_a', a_field='a_field') b = B.objects.create(name='b', lots_of_text='lots_of_text_b', b_field='b_field') c = C.objects.create(name='c', lots_of_text='lots_of_text_c', is_published=True, c_a=a, c_b=b) results = C.objects.all().only('name', 'lots_of_text', 'c_a', 'c_b', 'c_b__lots_of_text', 'c_a__name', 'c_b__name').select_related() self.assertSequenceEqual(results, [c]) with self.assertNumQueries(0): qs_c = results[0] self.assertEqual(qs_c.name, 'c') self.assertEqual(qs_c.lots_of_text, 'lots_of_text_c') self.assertEqual(qs_c.c_b.lots_of_text, 'lots_of_text_b') self.assertEqual(qs_c.c_a.name, 'a') self.assertEqual(qs_c.c_b.name, 'b') def test_regression_22508(self): building = Building.objects.create(name='101') device = Device.objects.create(name="router", building=building) Port.objects.create(port_number='1', device=device) device = Device.objects.get() port = device.port_set.select_related('device__building').get() with self.assertNumQueries(0): port.device.building