from __future__ import absolute_import, unicode_literals from django.test import TestCase from .models import (Building, Child, Device, Port, Item, Country, Connection, ClientStatus, State, Client, SpecialClient, TUser, Person, Student, Organizer, Class, Enrollment) 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, unicode(c.start), unicode(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, unicode(c.start), unicode(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) e = 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. """ australia = 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) i1 = Item.objects.create(name="item1", child=c1) i2 = 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) c1 = 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 sc1 = 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').get(name='Troy Buswell') self.assertEqual(troy.name, 'Troy Buswell') self.assertEqual(troy.value, 42) self.assertEqual(troy.state.name, 'Western Australia')