/tests/regressiontests/select_related_regress/tests.py

  1from django.test import TestCase
  2from regressiontests.select_related_regress.models import *
  3
  4class SelectRelatedRegressTests(TestCase):
  5
  6    def test_regression_7110(self):
  7        """
  8        Regression test for bug #7110.
  9
 10        When using select_related(), we must query the
 11        Device and Building tables using two different aliases (each) in order to
 12        differentiate the start and end Connection fields. The net result is that
 13        both the "connections = ..." queries here should give the same results
 14        without pulling in more than the absolute minimum number of tables
 15        (history has shown that it's easy to make a mistake in the implementation
 16        and include some unnecessary bonus joins).
 17        """
 18
 19        b=Building.objects.create(name='101')
 20        dev1=Device.objects.create(name="router", building=b)
 21        dev2=Device.objects.create(name="switch", building=b)
 22        dev3=Device.objects.create(name="server", building=b)
 23        port1=Port.objects.create(port_number='4',device=dev1)
 24        port2=Port.objects.create(port_number='7',device=dev2)
 25        port3=Port.objects.create(port_number='1',device=dev3)
 26        c1=Connection.objects.create(start=port1, end=port2)
 27        c2=Connection.objects.create(start=port2, end=port3)
 28
 29        connections=Connection.objects.filter(start__device__building=b, end__device__building=b).order_by('id')
 30        self.assertEqual([(c.id, unicode(c.start), unicode(c.end)) for c in connections],
 31            [(c1.id, u'router/4', u'switch/7'), (c2.id, u'switch/7', u'server/1')])
 32
 33        connections=Connection.objects.filter(start__device__building=b, end__device__building=b).select_related().order_by('id')
 34        self.assertEqual([(c.id, unicode(c.start), unicode(c.end)) for c in connections],
 35            [(c1.id, u'router/4', u'switch/7'), (c2.id, u'switch/7', u'server/1')])
 36
 37        # This final query should only join seven tables (port, device and building
 38        # twice each, plus connection once).
 39        self.assertEqual(connections.query.count_active_tables(), 7)
 40
 41
 42    def test_regression_8106(self):
 43        """
 44        Regression test for bug #8106.
 45
 46        Same sort of problem as the previous test, but this time there are
 47        more extra tables to pull in as part of the select_related() and some
 48        of them could potentially clash (so need to be kept separate).
 49        """
 50
 51        us = TUser.objects.create(name="std")
 52        usp = Person.objects.create(user=us)
 53        uo = TUser.objects.create(name="org")
 54        uop = Person.objects.create(user=uo)
 55        s = Student.objects.create(person = usp)
 56        o = Organizer.objects.create(person = uop)
 57        c = Class.objects.create(org=o)
 58        e = Enrollment.objects.create(std=s, cls=c)
 59
 60        e_related = Enrollment.objects.all().select_related()[0]
 61        self.assertEqual(e_related.std.person.user.name, u"std")
 62        self.assertEqual(e_related.cls.org.person.user.name, u"org")
 63
 64    def test_regression_8036(self):
 65        """
 66        Regression test for bug #8036
 67
 68        the first related model in the tests below
 69        ("state") is empty and we try to select the more remotely related
 70        state__country. The regression here was not skipping the empty column results
 71        for country before getting status.
 72        """
 73
 74        australia = Country.objects.create(name='Australia')
 75        active = ClientStatus.objects.create(name='active')
 76        client = Client.objects.create(name='client', status=active)
 77
 78        self.assertEqual(client.status, active)
 79        self.assertEqual(Client.objects.select_related()[0].status, active)
 80        self.assertEqual(Client.objects.select_related('state')[0].status, active)
 81        self.assertEqual(Client.objects.select_related('state', 'status')[0].status, active)
 82        self.assertEqual(Client.objects.select_related('state__country')[0].status, active)
 83        self.assertEqual(Client.objects.select_related('state__country', 'status')[0].status, active)
 84        self.assertEqual(Client.objects.select_related('status')[0].status, active)
 85
 86    def test_multi_table_inheritance(self):
 87        """ Exercising select_related() with multi-table model inheritance. """
 88        c1 = Child.objects.create(name="child1", value=42)
 89        i1 = Item.objects.create(name="item1", child=c1)
 90        i2 = Item.objects.create(name="item2")
 91
 92        self.assertQuerysetEqual(
 93                Item.objects.select_related("child").order_by("name"),
 94                ["<Item: item1>", "<Item: item2>"]
 95        )
 96
 97    def test_regression_12851(self):
 98        """
 99        Regression for #12851
100
101        Deferred fields are used correctly if you select_related a subset
102        of fields.
103        """
104        australia = Country.objects.create(name='Australia')
105        active = ClientStatus.objects.create(name='active')
106
107        wa = State.objects.create(name="Western Australia", country=australia)
108        c1 = Client.objects.create(name='Brian Burke', state=wa, status=active)
109        burke = Client.objects.select_related('state').defer('state__name').get(name='Brian Burke')
110
111        self.assertEqual(burke.name, u'Brian Burke')
112        self.assertEqual(burke.state.name, u'Western Australia')
113
114        # Still works if we're dealing with an inherited class
115        sc1 = SpecialClient.objects.create(name='Troy Buswell', state=wa, status=active, value=42)
116        troy = SpecialClient.objects.select_related('state').defer('state__name').get(name='Troy Buswell')
117
118        self.assertEqual(troy.name, u'Troy Buswell')
119        self.assertEqual(troy.value, 42)
120        self.assertEqual(troy.state.name, u'Western Australia')
121
122        # Still works if we defer an attribute on the inherited class
123        troy = SpecialClient.objects.select_related('state').defer('value', 'state__name').get(name='Troy Buswell')
124
125        self.assertEqual(troy.name, u'Troy Buswell')
126        self.assertEqual(troy.value, 42)
127        self.assertEqual(troy.state.name, u'Western Australia')
128
129        # Also works if you use only, rather than defer
130        troy = SpecialClient.objects.select_related('state').only('name').get(name='Troy Buswell')
131
132        self.assertEqual(troy.name, u'Troy Buswell')
133        self.assertEqual(troy.value, 42)
134        self.assertEqual(troy.state.name, u'Western Australia')