django/tests/null_fk/tests.py

68 lines
2.9 KiB
Python

from django.db.models import Q
from django.test import TestCase
from .models import Comment, Forum, Item, Post, PropertyValue, SystemDetails, SystemInfo
class NullFkTests(TestCase):
def test_null_fk(self):
d = SystemDetails.objects.create(details="First details")
s = SystemInfo.objects.create(system_name="First forum", system_details=d)
f = Forum.objects.create(system_info=s, forum_name="First forum")
p = Post.objects.create(forum=f, title="First Post")
c1 = Comment.objects.create(post=p, comment_text="My first comment")
c2 = Comment.objects.create(comment_text="My second comment")
# Starting from comment, make sure that a .select_related(...) with a specified
# set of fields will properly LEFT JOIN multiple levels of NULLs (and the things
# that come after the NULLs, or else data that should exist won't). Regression
# test for #7369.
c = Comment.objects.select_related().get(id=c1.id)
self.assertEqual(c.post, p)
self.assertIsNone(Comment.objects.select_related().get(id=c2.id).post)
self.assertQuerysetEqual(
Comment.objects.select_related("post__forum__system_info").all(),
[
(c1.id, "My first comment", "<Post: First Post>"),
(c2.id, "My second comment", "None"),
],
transform=lambda c: (c.id, c.comment_text, repr(c.post)),
)
# Regression test for #7530, #7716.
self.assertIsNone(
Comment.objects.select_related("post").filter(post__isnull=True)[0].post
)
self.assertQuerysetEqual(
Comment.objects.select_related("post__forum__system_info__system_details"),
[
(c1.id, "My first comment", "<Post: First Post>"),
(c2.id, "My second comment", "None"),
],
transform=lambda c: (c.id, c.comment_text, repr(c.post)),
)
def test_combine_isnull(self):
item = Item.objects.create(title="Some Item")
pv = PropertyValue.objects.create(label="Some Value")
item.props.create(key="a", value=pv)
item.props.create(key="b") # value=NULL
q1 = Q(props__key="a", props__value=pv)
q2 = Q(props__key="b", props__value__isnull=True)
# Each of these individually should return the item.
self.assertEqual(Item.objects.get(q1), item)
self.assertEqual(Item.objects.get(q2), item)
# Logically, qs1 and qs2, and qs3 and qs4 should be the same.
qs1 = Item.objects.filter(q1) & Item.objects.filter(q2)
qs2 = Item.objects.filter(q2) & Item.objects.filter(q1)
qs3 = Item.objects.filter(q1) | Item.objects.filter(q2)
qs4 = Item.objects.filter(q2) | Item.objects.filter(q1)
# Regression test for #15823.
self.assertEqual(list(qs1), list(qs2))
self.assertEqual(list(qs3), list(qs4))