From 3dd5e71752c993df00e01fca8086a1af5ba89176 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pave=C5=82=20Ty=C5=9Blacki?= <pavel.tyslacki@gmail.com>
Date: Mon, 11 Feb 2019 17:17:06 +0300
Subject: [PATCH] [2.2.x] Refs #30172 -- Prevented removing a field's check or
unique constraint from removing Meta constraints.
Backport of 4bb859e24694f6cb8974ed9d2225f18214338ea3 from master.
---
django/db/backends/base/features.py | 4 +
django/db/backends/base/schema.py | 17 ++++-
django/db/backends/oracle/features.py | 1 +
tests/schema/models.py | 7 ++
tests/schema/tests.py | 104 +++++++++++++++++++++++++-
5 files changed, 125 insertions(+), 8 deletions(-)
diff --git a/django/db/backends/base/features.py b/django/db/backends/base/features.py
index 8afc7eb516..99ab45f21c 100644
--- a/django/db/backends/base/features.py
+++ b/django/db/backends/base/features.py
@@ -281,6 +281,10 @@ class BaseDatabaseFeatures:
supports_partial_indexes = True
supports_functions_in_partial_indexes = True
+ # Does the database allow more than one constraint or index on the same
+ # field(s)?
+ allows_multiple_constraints_on_same_fields = True
+
def __init__(self, connection):
self.connection = connection
diff --git a/django/db/backends/base/schema.py b/django/db/backends/base/schema.py
index 113d1b7f67..19c9a04ba8 100644
--- a/django/db/backends/base/schema.py
+++ b/django/db/backends/base/schema.py
@@ -548,7 +548,11 @@ class BaseDatabaseSchemaEditor:
# Has unique been removed?
if old_field.unique and (not new_field.unique or self._field_became_primary_key(old_field, new_field)):
# Find the unique constraint for this field
- constraint_names = self._constraint_names(model, [old_field.column], unique=True, primary_key=False)
+ meta_constraint_names = {constraint.name for constraint in model._meta.constraints}
+ constraint_names = self._constraint_names(
+ model, [old_field.column], unique=True, primary_key=False,
+ exclude=meta_constraint_names,
+ )
if strict and len(constraint_names) != 1:
raise ValueError("Found wrong number (%s) of unique constraints for %s.%s" % (
len(constraint_names),
@@ -598,7 +602,11 @@ class BaseDatabaseSchemaEditor:
self.execute(self._delete_index_sql(model, index_name))
# Change check constraints?
if old_db_params['check'] != new_db_params['check'] and old_db_params['check']:
- constraint_names = self._constraint_names(model, [old_field.column], check=True)
+ meta_constraint_names = {constraint.name for constraint in model._meta.constraints}
+ constraint_names = self._constraint_names(
+ model, [old_field.column], check=True,
+ exclude=meta_constraint_names,
+ )
if strict and len(constraint_names) != 1:
raise ValueError("Found wrong number (%s) of check constraints for %s.%s" % (
len(constraint_names),
@@ -1089,7 +1097,7 @@ class BaseDatabaseSchemaEditor:
def _constraint_names(self, model, column_names=None, unique=None,
primary_key=None, index=None, foreign_key=None,
- check=None, type_=None):
+ check=None, type_=None, exclude=None):
"""Return all constraint names matching the columns and conditions."""
if column_names is not None:
column_names = [
@@ -1113,7 +1121,8 @@ class BaseDatabaseSchemaEditor:
continue
if type_ is not None and infodict['type'] != type_:
continue
- result.append(name)
+ if not exclude or name not in exclude:
+ result.append(name)
return result
def _delete_primary_key(self, model, strict=False):
diff --git a/django/db/backends/oracle/features.py b/django/db/backends/oracle/features.py
index ec301d9d37..55bf327440 100644
--- a/django/db/backends/oracle/features.py
+++ b/django/db/backends/oracle/features.py
@@ -56,6 +56,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
supports_ignore_conflicts = False
max_query_params = 2**16 - 1
supports_partial_indexes = False
+ allows_multiple_constraints_on_same_fields = False
@cached_property
def has_fetch_offset_support(self):
diff --git a/tests/schema/models.py b/tests/schema/models.py
index f6bdbd8815..2c277c681b 100644
--- a/tests/schema/models.py
+++ b/tests/schema/models.py
@@ -55,6 +55,13 @@ class AuthorWithIndexedName(models.Model):
apps = new_apps
+class AuthorWithUniqueName(models.Model):
+ name = models.CharField(max_length=255, unique=True)
+
+ class Meta:
+ apps = new_apps
+
+
class Book(models.Model):
author = models.ForeignKey(Author, models.CASCADE)
title = models.CharField(max_length=100, db_index=True)
diff --git a/tests/schema/tests.py b/tests/schema/tests.py
index 37f39ff7ed..6bcf3b5563 100644
--- a/tests/schema/tests.py
+++ b/tests/schema/tests.py
@@ -7,7 +7,8 @@ from unittest import mock
from django.db import (
DatabaseError, IntegrityError, OperationalError, connection,
)
-from django.db.models import Model
+from django.db.models import Model, Q
+from django.db.models.constraints import CheckConstraint, UniqueConstraint
from django.db.models.deletion import CASCADE, PROTECT
from django.db.models.fields import (
AutoField, BigAutoField, BigIntegerField, BinaryField, BooleanField,
@@ -31,9 +32,10 @@ from .fields import (
from .models import (
Author, AuthorCharFieldWithIndex, AuthorTextFieldWithIndex,
AuthorWithDefaultHeight, AuthorWithEvenLongerName, AuthorWithIndexedName,
- Book, BookForeignObj, BookWeak, BookWithLongName, BookWithO2O,
- BookWithoutAuthor, BookWithSlug, IntegerPK, Node, Note, NoteRename, Tag,
- TagIndexed, TagM2MTest, TagUniqueRename, Thing, UniqueTest, new_apps,
+ AuthorWithUniqueName, Book, BookForeignObj, BookWeak, BookWithLongName,
+ BookWithO2O, BookWithoutAuthor, BookWithSlug, IntegerPK, Node, Note,
+ NoteRename, Tag, TagIndexed, TagM2MTest, TagUniqueRename, Thing,
+ UniqueTest, new_apps,
)
@@ -1524,6 +1526,53 @@ class SchemaTests(TransactionTestCase):
if not any(details['columns'] == ['height'] and details['check'] for details in constraints.values()):
self.fail("No check constraint for height found")
+ @skipUnlessDBFeature('supports_column_check_constraints')
+ def test_remove_field_check_does_not_remove_meta_constraints(self):
+ with connection.schema_editor() as editor:
+ editor.create_model(Author)
+ # Add the custom check constraint
+ constraint = CheckConstraint(check=Q(height__gte=0), name='author_height_gte_0_check')
+ custom_constraint_name = constraint.name
+ Author._meta.constraints = [constraint]
+ with connection.schema_editor() as editor:
+ editor.add_constraint(Author, constraint)
+ # Ensure the constraints exist
+ constraints = self.get_constraints(Author._meta.db_table)
+ self.assertIn(custom_constraint_name, constraints)
+ other_constraints = [
+ name for name, details in constraints.items()
+ if details['columns'] == ['height'] and details['check'] and name != custom_constraint_name
+ ]
+ self.assertEqual(len(other_constraints), 1)
+ # Alter the column to remove field check
+ old_field = Author._meta.get_field('height')
+ new_field = IntegerField(null=True, blank=True)
+ new_field.set_attributes_from_name('height')
+ with connection.schema_editor() as editor:
+ editor.alter_field(Author, old_field, new_field, strict=True)
+ constraints = self.get_constraints(Author._meta.db_table)
+ self.assertIn(custom_constraint_name, constraints)
+ other_constraints = [
+ name for name, details in constraints.items()
+ if details['columns'] == ['height'] and details['check'] and name != custom_constraint_name
+ ]
+ self.assertEqual(len(other_constraints), 0)
+ # Alter the column to re-add field check
+ new_field2 = Author._meta.get_field('height')
+ with connection.schema_editor() as editor:
+ editor.alter_field(Author, new_field, new_field2, strict=True)
+ constraints = self.get_constraints(Author._meta.db_table)
+ self.assertIn(custom_constraint_name, constraints)
+ other_constraints = [
+ name for name, details in constraints.items()
+ if details['columns'] == ['height'] and details['check'] and name != custom_constraint_name
+ ]
+ self.assertEqual(len(other_constraints), 1)
+ # Drop the check constraint
+ with connection.schema_editor() as editor:
+ Author._meta.constraints = []
+ editor.remove_constraint(Author, constraint)
+
def test_unique(self):
"""
Tests removing and adding unique constraints to a single column.
@@ -1650,6 +1699,53 @@ class SchemaTests(TransactionTestCase):
with self.assertRaises(IntegrityError):
Tag.objects.create(title='bar', slug='foo')
+ @skipUnlessDBFeature('allows_multiple_constraints_on_same_fields')
+ def test_remove_field_unique_does_not_remove_meta_constraints(self):
+ with connection.schema_editor() as editor:
+ editor.create_model(AuthorWithUniqueName)
+ # Add the custom unique constraint
+ constraint = UniqueConstraint(fields=['name'], name='author_name_uniq')
+ custom_constraint_name = constraint.name
+ AuthorWithUniqueName._meta.constraints = [constraint]
+ with connection.schema_editor() as editor:
+ editor.add_constraint(AuthorWithUniqueName, constraint)
+ # Ensure the constraints exist
+ constraints = self.get_constraints(AuthorWithUniqueName._meta.db_table)
+ self.assertIn(custom_constraint_name, constraints)
+ other_constraints = [
+ name for name, details in constraints.items()
+ if details['columns'] == ['name'] and details['unique'] and name != custom_constraint_name
+ ]
+ self.assertEqual(len(other_constraints), 1)
+ # Alter the column to remove field uniqueness
+ old_field = AuthorWithUniqueName._meta.get_field('name')
+ new_field = CharField(max_length=255)
+ new_field.set_attributes_from_name('name')
+ with connection.schema_editor() as editor:
+ editor.alter_field(AuthorWithUniqueName, old_field, new_field, strict=True)
+ constraints = self.get_constraints(AuthorWithUniqueName._meta.db_table)
+ self.assertIn(custom_constraint_name, constraints)
+ other_constraints = [
+ name for name, details in constraints.items()
+ if details['columns'] == ['name'] and details['unique'] and name != custom_constraint_name
+ ]
+ self.assertEqual(len(other_constraints), 0)
+ # Alter the column to re-add field uniqueness
+ new_field2 = AuthorWithUniqueName._meta.get_field('name')
+ with connection.schema_editor() as editor:
+ editor.alter_field(AuthorWithUniqueName, new_field, new_field2, strict=True)
+ constraints = self.get_constraints(AuthorWithUniqueName._meta.db_table)
+ self.assertIn(custom_constraint_name, constraints)
+ other_constraints = [
+ name for name, details in constraints.items()
+ if details['columns'] == ['name'] and details['unique'] and name != custom_constraint_name
+ ]
+ self.assertEqual(len(other_constraints), 1)
+ # Drop the unique constraint
+ with connection.schema_editor() as editor:
+ AuthorWithUniqueName._meta.constraints = []
+ editor.remove_constraint(AuthorWithUniqueName, constraint)
+
def test_unique_together(self):
"""
Tests removing and adding unique_together constraints on a model.