From 0d86196e16a144f1085195b8bfe5a7b44a285851 Mon Sep 17 00:00:00 2001 From: David Beitey Date: Fri, 15 Jan 2021 19:03:26 +1000 Subject: [PATCH] Error on unsupported unique constraint conditions CREATE INDEX in SQL Server only supports AND conditions (not OR) as part of its WHERE syntax. This change handles that situation by raising an error from the schema editor class. This change adds unit tests to confirm this happens against a SQL Server database. Previously opened at https://github.com/ESSolutions/django-mssql-backend/pull/97 --- mssql/schema.py | 9 ++- .../0010_test_unique_constraints.py | 68 +++++++++++++++++++ testapp/models.py | 37 ++++++++++ testapp/tests/test_constraints.py | 61 ++++++++++++++++- 4 files changed, 171 insertions(+), 4 deletions(-) create mode 100644 testapp/migrations/0010_test_unique_constraints.py diff --git a/mssql/schema.py b/mssql/schema.py index e617cb5f..b7b27c4b 100644 --- a/mssql/schema.py +++ b/mssql/schema.py @@ -17,8 +17,9 @@ Table, ) from django import VERSION as django_version -from django.db.models import Index +from django.db.models import Index, UniqueConstraint from django.db.models.fields import AutoField, BigAutoField +from django.db.models.sql.where import AND from django.db.transaction import TransactionManagementError from django.utils.encoding import force_str @@ -955,3 +956,9 @@ def remove_field(self, model, field): for sql in list(self.deferred_sql): if isinstance(sql, Statement) and sql.references_column(model._meta.db_table, field.column): self.deferred_sql.remove(sql) + + def add_constraint(self, model, constraint): + if isinstance(constraint, UniqueConstraint) and constraint.condition and constraint.condition.connector != AND: + raise NotImplementedError("The backend does not support %s conditions on unique constraint %s." % + (constraint.condition.connector, constraint.name)) + super().add_constraint(model, constraint) diff --git a/testapp/migrations/0010_test_unique_constraints.py b/testapp/migrations/0010_test_unique_constraints.py new file mode 100644 index 00000000..6c84c05e --- /dev/null +++ b/testapp/migrations/0010_test_unique_constraints.py @@ -0,0 +1,68 @@ +# Generated by Django 3.1.5 on 2021-01-18 00:05 + +from django.db import migrations, models + + +class Migration(migrations.Migration): + + dependencies = [ + ('testapp', '0009_test_drop_table_with_foreign_key_reference_part2'), + ] + + operations = [ + migrations.CreateModel( + name='TestUnsupportableUniqueConstraint', + fields=[ + ( + 'id', + models.AutoField( + auto_created=True, + primary_key=True, + serialize=False, + verbose_name='ID', + ), + ), + ('_type', models.CharField(max_length=50)), + ('status', models.CharField(max_length=50)), + ], + options={ + 'managed': False, + }, + ), + migrations.CreateModel( + name='TestSupportableUniqueConstraint', + fields=[ + ( + 'id', + models.AutoField( + auto_created=True, + primary_key=True, + serialize=False, + verbose_name='ID', + ), + ), + ('_type', models.CharField(max_length=50)), + ('status', models.CharField(max_length=50)), + ], + ), + migrations.AddConstraint( + model_name='testsupportableuniqueconstraint', + constraint=models.UniqueConstraint( + condition=models.Q( + ('status', 'in_progress'), + ('status', 'needs_changes'), + ('status', 'published'), + ), + fields=('_type',), + name='and_constraint', + ), + ), + migrations.AddConstraint( + model_name='testsupportableuniqueconstraint', + constraint=models.UniqueConstraint( + condition=models.Q(status__in=['in_progress', 'needs_changes']), + fields=('_type',), + name='in_constraint', + ), + ), + ] diff --git a/testapp/models.py b/testapp/models.py index 85a571d3..3ef2be3a 100644 --- a/testapp/models.py +++ b/testapp/models.py @@ -4,6 +4,7 @@ import uuid from django.db import models +from django.db.models import Q from django.utils import timezone @@ -74,3 +75,39 @@ class TestRemoveOneToOneFieldModel(models.Model): # thats already is removed. # b = models.OneToOneField('self', on_delete=models.SET_NULL, null=True) a = models.CharField(max_length=50) + + +class TestUnsupportableUniqueConstraint(models.Model): + class Meta: + managed = False + constraints = [ + models.UniqueConstraint( + name='or_constraint', + fields=['_type'], + condition=(Q(status='in_progress') | Q(status='needs_changes')), + ), + ] + + _type = models.CharField(max_length=50) + status = models.CharField(max_length=50) + + +class TestSupportableUniqueConstraint(models.Model): + class Meta: + constraints = [ + models.UniqueConstraint( + name='and_constraint', + fields=['_type'], + condition=( + Q(status='in_progress') & Q(status='needs_changes') & Q(status='published') + ), + ), + models.UniqueConstraint( + name='in_constraint', + fields=['_type'], + condition=(Q(status__in=['in_progress', 'needs_changes'])), + ), + ] + + _type = models.CharField(max_length=50) + status = models.CharField(max_length=50) diff --git a/testapp/tests/test_constraints.py b/testapp/tests/test_constraints.py index 635fa1b1..2c743f11 100644 --- a/testapp/tests/test_constraints.py +++ b/testapp/tests/test_constraints.py @@ -1,12 +1,18 @@ # Copyright (c) Microsoft Corporation. # Licensed under the MIT license. +from django.db import connections, migrations, models +from django.db.migrations.state import ProjectState from django.db.utils import IntegrityError -from django.test import TestCase, skipUnlessDBFeature +from django.test import TestCase, TransactionTestCase, skipUnlessDBFeature +from mssql.base import DatabaseWrapper from ..models import ( - Author, Editor, Post, - TestUniqueNullableModel, TestNullableUniqueTogetherModel, + Author, + Editor, + Post, + TestUniqueNullableModel, + TestNullableUniqueTogetherModel, ) @@ -55,3 +61,52 @@ def test_after_type_change(self): TestNullableUniqueTogetherModel.objects.create(a='aaa', b='bbb', c='ccc') with self.assertRaises(IntegrityError): TestNullableUniqueTogetherModel.objects.create(a='aaa', b='bbb', c='ccc') + + +class TestUniqueConstraints(TransactionTestCase): + def test_unsupportable_unique_constraint(self): + # Only execute tests when running against SQL Server + connection = connections['default'] + if isinstance(connection, DatabaseWrapper): + + class TestMigration(migrations.Migration): + initial = True + + operations = [ + migrations.CreateModel( + name='TestUnsupportableUniqueConstraint', + fields=[ + ( + 'id', + models.AutoField( + auto_created=True, + primary_key=True, + serialize=False, + verbose_name='ID', + ), + ), + ('_type', models.CharField(max_length=50)), + ('status', models.CharField(max_length=50)), + ], + ), + migrations.AddConstraint( + model_name='testunsupportableuniqueconstraint', + constraint=models.UniqueConstraint( + condition=models.Q( + ('status', 'in_progress'), + ('status', 'needs_changes'), + _connector='OR', + ), + fields=('_type',), + name='or_constraint', + ), + ), + ] + + migration = TestMigration('testapp', 'test_unsupportable_unique_constraint') + + with connection.schema_editor(atomic=True) as editor: + with self.assertRaisesRegex( + NotImplementedError, "does not support OR conditions" + ): + return migration.apply(ProjectState(), editor)