[1.2.X] Migrated null_queries doctests. Thanks to Stephan Jaekel.

class Inner(models.Model):

    first = models.ForeignKey(OuterA)

    second = models.ForeignKey(OuterB, null=True)

__test__ = {'API_TESTS':"""

# Regression test for the use of None as a query value. None is interpreted as

# an SQL NULL, but only in __exact queries.

# Set up some initial polls and choices

>>> p1 = Poll(question='Why?')

>>> p1.save()

>>> c1 = Choice(poll=p1, choice='Because.')

>>> c1.save()

>>> c2 = Choice(poll=p1, choice='Why Not?')

>>> c2.save()

# Exact query with value None returns nothing ("is NULL" in sql, but every 'id'

# field has a value).

>>> Choice.objects.filter(choice__exact=None)

[]

Excluding the previous result returns everything.

>>> Choice.objects.exclude(choice=None).order_by('id')

[<Choice: Choice: Because. in poll Q: Why? >, <Choice: Choice: Why Not? in poll Q: Why? >]

# Valid query, but fails because foo isn't a keyword

>>> Choice.objects.filter(foo__exact=None)

Traceback (most recent call last):

...

FieldError: Cannot resolve keyword 'foo' into field. Choices are: choice, id, poll

# Can't use None on anything other than __exact

>>> Choice.objects.filter(id__gt=None)

Traceback (most recent call last):

...

ValueError: Cannot use None as a query value

# Can't use None on anything other than __exact

>>> Choice.objects.filter(foo__gt=None)

Traceback (most recent call last):

...

ValueError: Cannot use None as a query value

# Related managers use __exact=None implicitly if the object hasn't been saved.

>>> p2 = Poll(question="How?")

>>> p2.choice_set.all()

[]

# Querying across reverse relations and then another relation should insert

# outer joins correctly so as not to exclude results.

>>> obj = OuterA.objects.create()

>>> OuterA.objects.filter(inner__second=None)

[<OuterA: OuterA object>]

>>> OuterA.objects.filter(inner__second__data=None)

[<OuterA: OuterA object>]

>>> _ = Inner.objects.create(first=obj)

>>> Inner.objects.filter(first__inner__second=None)

[<Inner: Inner object>]

"""}

from django.test import TestCase

from django.core.exceptions import FieldError

from regressiontests.null_queries.models import *

class NullQueriesTests(TestCase):

    def test_none_as_null(self):

        """

        Regression test for the use of None as a query value.

        None is interpreted as an SQL NULL, but only in __exact queries.

        Set up some initial polls and choices

        """

        p1 = Poll(question='Why?')

        p1.save()

        c1 = Choice(poll=p1, choice='Because.')

        c1.save()

        c2 = Choice(poll=p1, choice='Why Not?')

        c2.save()

        # Exact query with value None returns nothing ("is NULL" in sql,

        # but every 'id' field has a value).

        self.assertQuerysetEqual(Choice.objects.filter(choice__exact=None), [])

        # Excluding the previous result returns everything.

        self.assertQuerysetEqual(

                Choice.objects.exclude(choice=None).order_by('id'),

                [

                    '<Choice: Choice: Because. in poll Q: Why? >',

                    '<Choice: Choice: Why Not? in poll Q: Why? >'

                ]

        )

        # Valid query, but fails because foo isn't a keyword

        self.assertRaises(FieldError, Choice.objects.filter, foo__exact=None)

        # Can't use None on anything other than __exact

        self.assertRaises(ValueError, Choice.objects.filter, id__gt=None)

        # Can't use None on anything other than __exact

        self.assertRaises(ValueError, Choice.objects.filter, foo__gt=None)

        # Related managers use __exact=None implicitly if the object hasn't been saved.

        p2 = Poll(question="How?")

        self.assertEquals(repr(p2.choice_set.all()), '[]')

    def test_reverse_relations(self):

        """

        Querying across reverse relations and then another relation should

        insert outer joins correctly so as not to exclude results.

        """

        obj = OuterA.objects.create()

        self.assertQuerysetEqual(

            OuterA.objects.filter(inner__second=None),

            ['<OuterA: OuterA object>']

        )

        self.assertQuerysetEqual(

            OuterA.objects.filter(inner__second__data=None),

            ['<OuterA: OuterA object>']

        )

        inner_obj = Inner.objects.create(first=obj)

        self.assertQuerysetEqual(

            Inner.objects.filter(first__inner__second=None),

            ['<Inner: Inner object>']

        )