def test_default_db_type(self):
     connection = type('connection', (object, ), {})
     field = JSONField()
     connection.vendor = 'postgresql'
     self.assertEqual(field.default_db_type(connection), 'jsonb')
     connection.vendor = 'mysql'
     self.assertEqual(field.default_db_type(connection), 'longtext')
     connection.vendor = 'oracle'
     self.assertEqual(field.default_db_type(connection), 'long')
     connection.vendor = 'random'
     self.assertEqual(field.default_db_type(connection), 'text')