Question

我有下表：

+-----------+--------+------+--------+----------+----------+---------+-------+
| player_id | europe | asia | africa | namerica | lamerica | oceania | total |
+-----------+--------+------+--------+----------+----------+---------+-------+
|    121693 |   1076 | 70   | NULL   | NULL     | NULL     | NULL    |  1146 |
|    121693 |    416 | 70   | NULL   | NULL     | NULL     | NULL    |   486 |
|    121693 |     40 | NULL | NULL   | NULL     | NULL     | NULL    |    40 |
|    118840 |     40 | NULL | NULL   | NULL     | NULL     | NULL    |    40 |
|    121693 |     40 | 70   | NULL   | NULL     | NULL     | NULL    |   110 |
|    118840 |     40 | 490  | NULL   | NULL     | NULL     | NULL    |   530 |
|    121691 |     96 | 0    | NULL   | NULL     | NULL     | NULL    |    96 |
|    121693 |    136 | 70   | NULL   | NULL     | NULL     | NULL    |   206 |
|    118840 |     40 | NULL | NULL   | NULL     | NULL     | NULL    |    40 |
|    121691 |     96 | NULL | NULL   | NULL     | NULL     | NULL    |    96 |
+-----------+--------+------+--------+----------+----------+---------+-------+

我想得到的是：

+-----------+--------+------+--------+----------+----------+---------+-------+
| player_id | europe | asia | africa | namerica | lamerica | oceania | total |
+-----------+--------+------+--------+----------+----------+---------+-------+
|    121693 |   1076 |   70 | NULL   | NULL     | NULL     | NULL    |  1146 |
|    118840 |     40 |  490 | NULL   | NULL     | NULL     | NULL    |   530 |
|    121691 |     96 |    0 | NULL   | NULL     | NULL     | NULL    |    96 |
+-----------+--------+------+--------+----------+----------+---------+-------+

我尝试了以下内容，但结果并不是我所需要的。

SELECT player_id, europe, asia, africa, namerica, 
                lamerica, oceania, MAX(total) AS total 
FROM tbl 
WHERE total IS NOT NULL 
GROUP BY player_id 
ORDER BY total DESC

这是结果

+-----------+--------+------+--------+----------+----------+---------+-------+
| player_id | europe | asia | africa | namerica | lamerica | oceania | total |
+-----------+--------+------+--------+----------+----------+---------+-------+
|    121693 |   1076 |   70 | NULL   | NULL     | NULL     | NULL    |  1146 |
|    118840 |     40 |      | NULL   | NULL     | NULL     | NULL    |   530 |
|    121691 |     96 |    0 | NULL   | NULL     | NULL     | NULL    |     96 |
+-----------+--------+------+--------+----------+----------+---------+-------+

请注意我使用的是MySQL视图。 MySQL中的视图不允许子查询。

修改

根据之前的建议，我试过这个：

SELECT a.player_id, a.europe, a.asia, a.africa, a.lamerica, a.namerica,    a.oceania, a.total 
FROM tbl AS a 
INNER JOIN (
    SELECT player_id, MAX(total) AS total 
    FROM tbl 
    GROUP BY player_id) b
ON a.player_id = b.player_id AND a.total = b.total

但我得到了这些结果：

+-----------+--------+------+--------+----------+----------+---------+-------+
| player_id | europe | asia | africa | lamerica | namerica | oceania | total |
+-----------+--------+------+--------+----------+----------+---------+-------+
|    121693 |   1076 | 70   | NULL   | NULL     | NULL     | NULL    |  1146 |
|    118840 |     40 | 490  | NULL   | NULL     | NULL     | NULL    |   530 |
|    121691 |     96 | NULL | NULL   | NULL     | NULL     | NULL    |   96  |
|    121691 |     96 | 0    | NULL   | NULL     | NULL     | NULL    |    96 |
+-----------+--------+------+--------+----------+----------+---------+-------+

它还返回平局。 如何避免这种情况？

Answer 1

在查询中添加另一个GROUP BY a.player_id：

SELECT a.player_id, a.europe, a.asia, a.africa, a.lamerica, a.namerica,    a.oceania, a.total 
FROM tbl AS a 
INNER JOIN (
    SELECT player_id, MAX(total) AS total 
    FROM tbl 
    GROUP BY player_id) b
ON a.player_id = b.player_id AND a.total = b.total
GROUP BY a.player_id

这将从带有关系的行中任意选择其他列的内容。

如果您启用了ONLY_FULL_GROUP_BY SQL模式（默认情况下默认情况下从MySQL 5.7开始），您需要使用ANY_VALUE来表明这是正常的。

SELECT a.player_id, ANY_VALUE(a.europe), ANY_VALUE(a.asia), ANY_VALUE(a.africa), ANY_VALUE(a.lamerica), ANY_VALUE(a.namerica), ANY_VALUE(a.oceania), ANY_VALUE(a.total)

在不使用子查询（mysql）的情况下按不同记录的最大值排序

1 个答案: