Question

问题：

我有一张桌子上有一些比赛结果。对于每辆车，有两名车手各自分别赢得积分。为了方便工作，我为每辆车创建了一个表格（因此两个驱动程序分为两列：driver1，driver2）而不是每个驱动程序一个，因为除了驱动程序之外，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   |
+------+-----+---------+---------+--------+

正如你所看到的，对于1号车来说，有两个以上的车手。所以当我想看到两个赛车中每个车手的总得分时，结果应该是这样的：

迈克尔：40
瑞克：20
Josh：20
史蒂夫：16
汤姆：16

但是如何为每个处理两列驱动程序（driver1和driver2）的驱动程序分数？或者我只需要更改我的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

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

Answer 2

您可以使用union all运算符将驱动程序作为单个列进行查询，然后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

分组由两列

2 个答案: