连接来自同一表的两个组字段

Question

我有一张小桌子“ Player 1”，其中有两个字段“ week 1”，“ week 2”是固定的。

桌面播放器1

Week 1    Week 2
 $ 50
 $ 50      $ 50
 $ 100     $ 100
 $ 100     $ 200

我想COUNT这两个字段“第1周”和“第2周”，并且我要看起来像这样：

 fixed  COUNT week 1   COUNT week 2
$ 50         2              1
$ 100        2              1
$ 200        0              1

Answer 1

您可以使用union all和group by：

select fixed, sum(isweek1) as week1, sum(isweek2) as week2
from (select week1 as fixed, 1 as isweek1, 0 as isweek2
      from t
      union all
      select week2, 0 as isweek1, 1 as isweek2
      from t
     ) as x
group by fixed;