Fixed #22460 -- Explicity remove constraints when dropping a related field. (0e45669f) · Commits · Dom Sekotill / django

django/db/backends/schema.py

+10 −2

Original line number	Diff line number	Diff line
		@@ -442,8 +442,16 @@ class BaseDatabaseSchemaEditor(object):
		# It might not actually have a column behind it
		if field.db_parameters(connection=self.connection)['type'] is None:
		return
		# Get the column's definition
		definition, params = self.column_sql(model, field)
		# Drop any FK constraints, MySQL requires explicit deletion
		if field.rel:
		fk_names = self._constraint_names(model, [field.column], foreign_key=True)
		for fk_name in fk_names:
		self.execute(
		self.sql_delete_fk % {
		"table": self.quote_name(model._meta.db_table),
		"name": fk_name,
		}
		)
		# Delete the column
		sql = self.sql_delete_column % {
		"table": self.quote_name(model._meta.db_table),

+16 −0

Original line number	Diff line number	Diff line
		@@ -416,6 +416,22 @@ class OperationTests(MigrationTestBase):
		operation.database_backwards("test_rmfl", editor, new_state, project_state)
		self.assertColumnExists("test_rmfl_pony", "pink")

		def test_remove_fk(self):
		"""
		Tests the RemoveField operation on a foreign key.
		"""
		project_state = self.set_up_test_model("test_rfk", related_model=True)
		self.assertColumnExists("test_rfk_rider", "pony_id")
		operation = migrations.RemoveField("Rider", "pony")
		new_state = project_state.clone()
		operation.state_forwards("test_rfk", new_state)
		with connection.schema_editor() as editor:
		operation.database_forwards("test_rfk", editor, project_state, new_state)
		self.assertColumnNotExists("test_rfk_rider", "pony_id")
		with connection.schema_editor() as editor:
		operation.database_backwards("test_rfk", editor, new_state, project_state)
		self.assertColumnExists("test_rfk_rider", "pony_id")

		def test_alter_model_table(self):
		"""
		Tests the AlterModelTable operation.