Support for index_together in schema backends (6a8cfbf0) · Commits · Dom Sekotill / django

django/db/backends/schema.py

+35 −1

Original line number	Diff line number	Diff line
		@@ -84,7 +84,7 @@ class BaseDatabaseSchemaEditor(object):
		# Get the cursor
		cursor = self.connection.cursor()
		# Log the command we're running, then run it
		logger.info("%s; (params %r)" % (sql, params))
		logger.debug("%s; (params %r)" % (sql, params))
		cursor.execute(sql, params)

		def quote_name(self, name):
		@@ -253,6 +253,40 @@ class BaseDatabaseSchemaEditor(object):
		"columns": ", ".join(self.quote_name(column) for column in columns),
		})

		def alter_index_together(self, model, old_index_together, new_index_together):
		"""
		Deals with a model changing its index_together.
		Note: The input index_togethers must be doubly-nested, not the single-
		nested ["foo", "bar"] format.
		"""
		olds = set(frozenset(fields) for fields in old_index_together)
		news = set(frozenset(fields) for fields in new_index_together)
		# Deleted indexes
		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), index=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_index % {
		"table": self.quote_name(model._meta.db_table),
		"name": constraint_names[0],
		},
		)
		# Created indexes
		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_index % {
		"table": self.quote_name(model._meta.db_table),
		"name": self._create_index_name(model, columns, suffix="_idx"),
		"columns": ", ".join(self.quote_name(column) for column in columns),
		"extra": "",
		})

		def alter_db_table(self, model, old_db_table, new_db_table):
		"""
		Renames the table a model points to.

tests/schema/tests.py

+51 −0

Original line number	Diff line number	Diff line
		@@ -452,6 +452,57 @@ class SchemaTests(TransactionTestCase):
		self.assertRaises(IntegrityError, UniqueTest.objects.create, year=2012, slug="foo")
		UniqueTest.objects.all().delete()

		def test_index_together(self):
		"""
		Tests removing and adding index_together constraints on a model.
		"""
		# Create the table
		with connection.schema_editor() as editor:
		editor.create_model(Tag)
		# Ensure there's no index on the year/slug columns first
		self.assertEqual(
		False,
		any(
		c["index"]
		for c in connection.introspection.get_constraints(connection.cursor(), "schema_tag").values()
		if c['columns'] == set(["slug", "title"])
		),
		)
		# Alter the model to add an index
		with connection.schema_editor() as editor:
		editor.alter_index_together(
		Tag,
		[],
		[("slug", "title")],
		)
		# Ensure there is now an index
		self.assertEqual(
		True,
		any(
		c["index"]
		for c in connection.introspection.get_constraints(connection.cursor(), "schema_tag").values()
		if c['columns'] == set(["slug", "title"])
		),
		)
		# Alter it back
		new_new_field = SlugField(unique=True)
		new_new_field.set_attributes_from_name("slug")
		with connection.schema_editor() as editor:
		editor.alter_unique_together(
		Tag,
		[("slug", "title")],
		[],
		)
		# Ensure there's no index
		self.assertEqual(
		False,
		any(
		c["index"]
		for c in connection.introspection.get_constraints(connection.cursor(), "schema_tag").values()
		if c['columns'] == set(["slug", "title"])
		),
		)

		def test_db_table(self):
		"""
		Tests renaming of the table