两列分组的Mysql问题

Question

问题：

我有一张表格，上面有一些比赛结果。每辆车有两名车手分别赢得积分。为了方便工作，我为每辆车创建了一个表格（因此在两列中有两个司机：driver1，driver2），而不是为每个司机一个，因为除了司机之外，所有其他列都具有相同的值每辆车。

示例：

+------+-----+---------+---------+--------+
| race | car | driver1 | driver2 | points | + other variables with same value for both drivers
+------+-----+---------+---------+--------+
| GER  |   1 | Michael | Rick    |   20   |
| GER  |   2 | Steve   | Tom     |    8   |
| JAP  |   1 | Michael | Josh    |   20   |
| JAP  |   2 | Steve   | Tom     |    8   |
+------+-----+---------+---------+--------+

如您所见，1 号车有两个以上的车手。所以当我想查看每个车手在两场比赛中的总分时，结果应该是这样的：

1. 迈克尔：40
2. 瑞克：20
3. 乔希：20
4. 史蒂夫：16
5. 汤姆：16

但是，如何对处理两列驱动程序（驱动程序 1 和驱动程序 2）的每个驱动程序的分数进行分组？还是我只需要更改表并为每个驱动程序创建一行？

$sql = "SELECT race, driver1, driver2, points FROM `example-table` GROUP BY ………. ORDER BY `points` DESC";

Answer 1

您可以使用union all 运算符将驱动程序作为单列查询，然后使用group by 驱动程序和sum 点：

SELECT   driver, SUM(points)
FROM     (SELECT driver1 AS driver, points FROM example_table
          UNION ALL
          SELECT driver2 AS driver, points FROM example_table) t
GROUP BY driver
ORDER BY 2 DESC

Answer 2

SELECT driver, SUM(points) as points
FROM
    (SELECT driver1 as driver, points
    FROM `example-table`
    UNION ALL
    SELECT driver2 as driver, points
    FROM `example-table`)T
GROUP BY driver