mysql - 有聚合函数时如何获得最大时间？

Question

我有一个这样的表:

// mytable
+----+------+-------+-------------+
| id | type | score |  unix_time  |
+----+------+-------+-------------+
| 1  | 1    | 5     | 1463508841  |  -- this (current output)
| 2  | 1    | 10    | 1463508842  |
| 3  | 2    | 5     | 1463508843  |  -- this (current output)
| 4  | 1    | 5     | 1463508844  |
| 5  | 2    | 15    | 1463508845  |  -- this (expected output)
| 6  | 1    | 10    | 1463508846  |  -- this (expected output)
+----+------+-------+-------------+

这是我的查询:

SELECT SUM(score), unix_time
FROM mytable
WHERE 1
GROUP BY type

这是当前输出:

+-------+-------------+
| score |  unix_time  |
+-------+-------------+
| 30    | 1463508841  |
| 20    | 1463508843  |
+-------+-------------+

如您所见，输出包含第一行的 unix_time。但我正在尝试选择最棒的一个。

所以这是预期输出:

+-------+-------------+
| score |  unix_time  |
+-------+-------------+
| 30    | 1463508846  |
| 20    | 1463508845  |
+-------+-------------+

我该怎么做？

Answer 1

我认为你需要 sum(score) 和 max(unix_time) 作为分组值

SELECT type, SUM(score), max(unix_time)
FROM mytable
GROUP BY type

我省略了 1 因为看起来没有意义..