Split ignores_nulls_in_unique_constraints feature.

Oracle and SQL Server don't have exactly the same limitations. It's
worth treating them differently.
This commit is contained in:
Aymeric Augustin 2014-05-07 22:03:10 +02:00
parent c70a61eb49
commit cff59bedc2
6 changed files with 12 additions and 6 deletions

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@ -473,9 +473,14 @@ class BaseDatabaseFeatures(object):
# Does the backend distinguish between '' and None?
interprets_empty_strings_as_nulls = False
# Does the backend allow inserting duplicate NULL rows in a nullable
# unique field? All core backends implement this correctly, but other
# databases such as SQL Server do not.
supports_nullable_unique_constraints = True
# Does the backend allow inserting duplicate rows when a unique_together
# constraint exists, but one of the unique_together columns is NULL?
ignores_nulls_in_unique_constraints = True
# constraint exists and some fields are nullable but not all of them?
supports_partially_nullable_unique_constraints = True
can_use_chunked_reads = True
can_return_id_from_insert = False

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@ -107,7 +107,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
has_zoneinfo_database = pytz is not None
supports_bitwise_or = False
can_defer_constraint_checks = True
ignores_nulls_in_unique_constraints = False
supports_partially_nullable_unique_constraints = False
has_bulk_insert = True
supports_tablespaces = True
supports_sequence_reset = False

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@ -8,6 +8,7 @@ from .models import Tag, Celebrity, Fan, Staff, StaffTag
@skipUnlessDBFeature('can_distinct_on_fields')
@skipUnlessDBFeature('supports_nullable_unique_constraints')
class DistinctOnTests(TestCase):
def setUp(self):
t1 = Tag.objects.create(name='t1')

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@ -650,7 +650,7 @@ class UniqueTest(TestCase):
form = TripleForm({'left': '1', 'middle': '3', 'right': '1'})
self.assertTrue(form.is_valid())
@skipUnlessDBFeature('ignores_nulls_in_unique_constraints')
@skipUnlessDBFeature('supports_nullable_unique_constraints')
def test_unique_null(self):
title = 'I May Be Wrong But I Doubt It'
form = BookForm({'title': title, 'author': self.writer.pk})

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@ -671,7 +671,7 @@ class ModelFormsetTest(TestCase):
self.assertEqual(book1.title, 'Flowers of Evil')
self.assertEqual(book1.notes, 'English translation of Les Fleurs du Mal')
@skipUnlessDBFeature('ignores_nulls_in_unique_constraints')
@skipUnlessDBFeature('supports_partially_nullable_unique_constraints')
def test_inline_formsets_with_nullable_unique_together(self):
# Test inline formsets where the inline-edited object has a
# unique_together constraint with a nullable member

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@ -229,7 +229,7 @@ class OneToOneRegressionTests(TestCase):
# Several instances of the origin are only possible if database allows
# inserting multiple NULL rows for a unique constraint
if connection.features.ignores_nulls_in_unique_constraints:
if connection.features.supports_nullable_unique_constraints:
UndergroundBar.objects.create()
# When there are several instances of the origin