Python django.db.migrations 模块，AlterOrderWithRespectTo() 实例源码

def test_alter_order_with_respect_to(self):
        project_state = self.set_up_test_model()
        operation = migrations.AlterOrderWithRespectTo('Rider', 'pony')
        new_state = project_state.clone()
        operation.state_forwards('tests', new_state)
        self.assertColumnNotExists('tests_rider', '_order')
        with connection.schema_editor() as editor:
            operation.database_forwards('tests', editor, project_state, new_state)
        self.assertColumnExists('tests_rider', '_order')
        with connection.schema_editor() as editor:
            operation.database_backwards('tests', editor, new_state, project_state)
        self.assertColumnNotExists('tests_rider', '_order')