求优化sql
表A:
| id | start_location_id | end_location_id |
| 1 | 1 | 2 |
| 2 | 1 | 3 |
表B:
| id | location_name |
| 1 | 北京 |
| 2 | 上海 |
| 3 | 成都 |
想要结果就是就是把start_location_id、end_location_id换location_name
结果
| id | start_location_name | end_location_name |
| 1 | 北京 | 上海 |
| 2 | 北京 | 成都 |
除了2次left join表B和子查询2次外,有没有其他更好的sql啊?