python/lib/django_1_4/tests/regressiontests/null_fk/tests.py

   1 from __future__ import absolute_import
   2
   3 from django.db.models import Q
   4 from django.test import TestCase
   5
   6 from .models import (SystemDetails, Item, PropertyValue, SystemInfo, Forum,
   7     Post, Comment)
   8
   9
  10 class NullFkTests(TestCase):
  11
  12     def test_null_fk(self):
  13         d = SystemDetails.objects.create(details='First details')
  14         s = SystemInfo.objects.create(system_name='First forum', system_details=d)
  15         f = Forum.objects.create(system_info=s, forum_name='First forum')
  16         p = Post.objects.create(forum=f, title='First Post')
  17         c1 = Comment.objects.create(post=p, comment_text='My first comment')
  18         c2 = Comment.objects.create(comment_text='My second comment')
  19
  20         # Starting from comment, make sure that a .select_related(...) with a specified
  21         # set of fields will properly LEFT JOIN multiple levels of NULLs (and the things
  22         # that come after the NULLs, or else data that should exist won't). Regression
  23         # test for #7369.
  24         c = Comment.objects.select_related().get(id=c1.id)
  25         self.assertEqual(c.post, p)
  26         self.assertEqual(Comment.objects.select_related().get(id=c2.id).post, None)
  27
  28         self.assertQuerysetEqual(
  29             Comment.objects.select_related('post__forum__system_info').all(),
  30             [
  31                 (c1.id, u'My first comment', '<Post: First Post>'),
  32                 (c2.id, u'My second comment', 'None')
  33             ],
  34             transform = lambda c: (c.id, c.comment_text, repr(c.post))
  35         )
  36
  37         # Regression test for #7530, #7716.
  38         self.assertTrue(Comment.objects.select_related('post').filter(post__isnull=True)[0].post is None)
  39
  40         self.assertQuerysetEqual(
  41             Comment.objects.select_related('post__forum__system_info__system_details'),
  42             [
  43                 (c1.id, u'My first comment', '<Post: First Post>'),
  44                 (c2.id, u'My second comment', 'None')
  45             ],
  46             transform = lambda c: (c.id, c.comment_text, repr(c.post))
  47         )
  48
  49     def test_combine_isnull(self):
  50         item = Item.objects.create(title='Some Item')
  51         pv = PropertyValue.objects.create(label='Some Value')
  52         item.props.create(key='a', value=pv)
  53         item.props.create(key='b') # value=NULL
  54         q1 = Q(props__key='a', props__value=pv)
  55         q2 = Q(props__key='b', props__value__isnull=True)
  56
  57         # Each of these individually should return the item.
  58         self.assertEqual(Item.objects.get(q1), item)
  59         self.assertEqual(Item.objects.get(q2), item)
  60
  61         # Logically, qs1 and qs2, and qs3 and qs4 should be the same.
  62         qs1 = Item.objects.filter(q1) & Item.objects.filter(q2)
  63         qs2 = Item.objects.filter(q2) & Item.objects.filter(q1)
  64         qs3 = Item.objects.filter(q1) | Item.objects.filter(q2)
  65         qs4 = Item.objects.filter(q2) | Item.objects.filter(q1)
  66
  67         # Regression test for #15823.
  68         self.assertEqual(list(qs1), list(qs2))
  69         self.assertEqual(list(qs3), list(qs4))