Add support for unique_together (c4b2a326) · Commits · Dom Sekotill / django

django/db/backends/schema.py

+52 −1

Original line number	Diff line number	Diff line
		@@ -29,6 +29,7 @@ class BaseDatabaseSchemaEditor(object):

		# Overrideable SQL templates
		sql_create_table = "CREATE TABLE %(table)s (%(definition)s)"
		sql_create_table_unique = "UNIQUE (%(columns)s)"
		sql_rename_table = "ALTER TABLE %(old_table)s RENAME TO %(new_table)s"
		sql_delete_table = "DROP TABLE %(table)s CASCADE"

		@@ -51,7 +52,7 @@ class BaseDatabaseSchemaEditor(object):
		sql_create_fk = "ALTER TABLE %(table)s ADD CONSTRAINT %(name)s FOREIGN KEY (%(column)s) REFERENCES %(to_table)s (%(to_column)s) DEFERRABLE INITIALLY DEFERRED"
		sql_delete_fk = "ALTER TABLE %(table)s DROP CONSTRAINT %(name)s"

		sql_create_index = "CREATE %(unique)s INDEX %(name)s ON %(table)s (%(columns)s)%s;"
		sql_create_index = "CREATE %(unique)s INDEX %(name)s ON %(table)s (%(columns)s)%(extra)s;"
		sql_delete_index = "DROP INDEX %(name)s"

		sql_create_pk = "ALTER TABLE %(table)s ADD CONSTRAINT %(constraint)s PRIMARY KEY (%(columns)s)"
		@@ -174,6 +175,17 @@ class BaseDatabaseSchemaEditor(object):
		definition,
		))
		params.extend(extra_params)
		# Indexes
		if field.db_index:
		self.deferred_sql.append(
		self.sql_create_index % {
		"unique": "",
		"name": self._create_index_name(model, [field.column], suffix=""),
		"table": self.quote_name(model._meta.db_table),
		"columns": self.quote_name(field.column),
		"extra": "",
		}
		)
		# FK
		if field.rel:
		to_table = field.rel.to._meta.db_table
		@@ -191,6 +203,12 @@ class BaseDatabaseSchemaEditor(object):
		"to_column": self.quote_name(to_column),
		}
		)
		# Add any unique_togethers
		for fields in model._meta.unique_together:
		columns = [model._meta.get_field_by_name(field)[0].column for field in fields]
		column_sqls.append(self.sql_create_table_unique % {
		"columns": ", ".join(self.quote_name(column) for column in columns),
		})
		# Make the table
		sql = self.sql_create_table % {
		"table": model._meta.db_table,
		@@ -210,6 +228,39 @@ class BaseDatabaseSchemaEditor(object):
		"table": self.quote_name(model._meta.db_table),
		})

		def alter_unique_together(self, model, old_unique_together, new_unique_together):
		"""
		Deals with a model changing its unique_together.
		Note: The input unique_togethers must be doubly-nested, not the single-
		nested ["foo", "bar"] format.
		"""
		olds = set(frozenset(fields) for fields in old_unique_together)
		news = set(frozenset(fields) for fields in new_unique_together)
		# Deleted uniques
		for fields in olds.difference(news):
		columns = [model._meta.get_field_by_name(field)[0].column for field in fields]
		constraint_names = self._constraint_names(model, list(columns), unique=True)
		if len(constraint_names) != 1:
		raise ValueError("Found wrong number (%s) of constraints for %s(%s)" % (
		len(constraint_names),
		model._meta.db_table,
		", ".join(columns),
		))
		self.execute(
		self.sql_delete_unique % {
		"table": self.quote_name(model._meta.db_table),
		"name": constraint_names[0],
		},
		)
		# Created uniques
		for fields in news.difference(olds):
		columns = [model._meta.get_field_by_name(field)[0].column for field in fields]
		self.execute(self.sql_create_unique % {
		"table": self.quote_name(model._meta.db_table),
		"name": self._create_index_name(model, columns, suffix="_uniq"),
		"columns": ", ".join(self.quote_name(column) for column in columns),
		})

		def create_field(self, model, field, keep_default=False):
		"""
		Creates a field on a model.

tests/modeltests/schema/models.py

+12 −0

Original line number	Diff line number	Diff line
		@@ -32,3 +32,15 @@ class Book(models.Model):
		class Tag(models.Model):
		title = models.CharField(max_length=255)
		slug = models.SlugField(unique=True)

		class Meta:
		managed = False


		class UniqueTest(models.Model):
		year = models.IntegerField()
		slug = models.SlugField(unique=False)

		class Meta:
		managed = False
		unique_together = ["year", "slug"]

tests/modeltests/schema/tests.py

+46 −2

Original line number	Diff line number	Diff line
		@@ -6,7 +6,7 @@ from django.db import connection, DatabaseError, IntegrityError
		from django.db.models.fields import IntegerField, TextField, CharField, SlugField
		from django.db.models.fields.related import ManyToManyField
		from django.db.models.loading import cache
		from .models import Author, Book, AuthorWithM2M, Tag
		from .models import Author, Book, AuthorWithM2M, Tag, UniqueTest


		class SchemaTests(TestCase):
		@@ -18,7 +18,7 @@ class SchemaTests(TestCase):
		as the code it is testing.
		"""

		models = [Author, Book, AuthorWithM2M, Tag]
		models = [Author, Book, AuthorWithM2M, Tag, UniqueTest]

		# Utility functions

		@@ -298,3 +298,47 @@ class SchemaTests(TestCase):
		Tag.objects.create(title="foo", slug="foo")
		self.assertRaises(IntegrityError, Tag.objects.create, title="bar", slug="foo")
		connection.rollback()

		def test_unique_together(self):
		"""
		Tests removing and adding unique_together constraints on a model.
		"""
		# Create the table
		editor = connection.schema_editor()
		editor.start()
		editor.create_model(UniqueTest)
		editor.commit()
		# Ensure the fields are unique to begin with
		UniqueTest.objects.create(year=2012, slug="foo")
		UniqueTest.objects.create(year=2011, slug="foo")
		UniqueTest.objects.create(year=2011, slug="bar")
		self.assertRaises(IntegrityError, UniqueTest.objects.create, year=2012, slug="foo")
		connection.rollback()
		# Alter the model to it's non-unique-together companion
		editor = connection.schema_editor()
		editor.start()
		editor.alter_unique_together(
		UniqueTest,
		UniqueTest._meta.unique_together,
		[],
		)
		editor.commit()
		# Ensure the fields are no longer unique
		UniqueTest.objects.create(year=2012, slug="foo")
		UniqueTest.objects.create(year=2012, slug="foo")
		connection.rollback()
		# Alter it back
		new_new_field = SlugField(unique=True)
		new_new_field.set_attributes_from_name("slug")
		editor = connection.schema_editor()
		editor.start()
		editor.alter_unique_together(
		UniqueTest,
		[],
		UniqueTest._meta.unique_together,
		)
		editor.commit()
		# Ensure the fields are unique again
		UniqueTest.objects.create(year=2012, slug="foo")
		self.assertRaises(IntegrityError, UniqueTest.objects.create, year=2012, slug="foo")
		connection.rollback()