mysql - 按 2 个日期字段一起排序

Question

表:

id | date_in             | date_out            |
1  | 2016-01-01 12:00:00 | 2016-01-03 12:00:00 |
2  | 2016-01-01 12:00:00 | 2016-01-02 12:00:00 |

我需要一个返回结果如下的查询:

id | alias
1  | 2016-01-01 12:00:00
2  | 2016-01-01 12:00:00
2  | 2016-01-02 12:00:00
1  | 2016-01-03 12:00:00

Answer 1

我会假设类似union 的东西就足够了，因为没有上下文我只能假设这就是您要找的东西？

SELECT t.id, t.date_in AS alias FROM test t
UNION ALL
SELECT t2.id, t2.date_out AS alias FROM test t2
ORDER BY alias ASC;

会给你如下结果:

+----+---------------------+
| id | alias               |
+----+---------------------+
|  2 | 2016-01-01 12:00:00 |
|  1 | 2016-01-01 12:00:00 |
|  2 | 2016-01-02 12:00:00 |
|  1 | 2016-01-03 12:00:00 |
+----+---------------------+
4 rows in set (0.00 sec)