/tests/modeltests/reverse_lookup/tests.py

 1from django.test import TestCase
 2from django.core.exceptions import FieldError
 3
 4from models import User, Poll, Choice
 5
 6class ReverseLookupTests(TestCase):
 7
 8    def setUp(self):
 9        john = User.objects.create(name="John Doe")
10        jim = User.objects.create(name="Jim Bo")
11        first_poll = Poll.objects.create(
12            question="What's the first question?",
13            creator=john
14        )
15        second_poll = Poll.objects.create(
16            question="What's the second question?",
17            creator=jim
18        )
19        new_choice = Choice.objects.create(
20            poll=first_poll,
21            related_poll=second_poll,
22            name="This is the answer."
23        )
24
25    def test_reverse_by_field(self):
26        u1 = User.objects.get(
27            poll__question__exact="What's the first question?"
28        )
29        self.assertEqual(u1.name, "John Doe")
30
31        u2 = User.objects.get(
32            poll__question__exact="What's the second question?"
33        )
34        self.assertEqual(u2.name, "Jim Bo")
35
36    def test_reverse_by_related_name(self):
37        p1 = Poll.objects.get(poll_choice__name__exact="This is the answer.")
38        self.assertEqual(p1.question, "What's the first question?")
39
40        p2 = Poll.objects.get(
41            related_choice__name__exact="This is the answer.")
42        self.assertEqual(p2.question, "What's the second question?")
43
44    def test_reverse_field_name_disallowed(self):
45        """
46        If a related_name is given you can't use the field name instead
47        """
48        self.assertRaises(FieldError, Poll.objects.get,
49            choice__name__exact="This is the answer")