Question

原始表很大，所以我会简化它：

mytable的：

CONDITION SIZE 
1          10
9          10
9          10
1          20
9          20
1          20
1          30

使用类似于

的查询

SELECT
  CASE WHEN CONDITION=1 THEN 'OK' ELSE 'BAD' END AS Status,
  SUM (CASE WHEN SIZE=10 THEN 1 ELSE 0 END) AS Small,
  SUM (CASE WHEN SIZE=20 THEN 1 ELSE 0 END) AS Medium,
  SUM (CASE WHEN SIZE=30 THEN 1 ELSE 0 END) AS Large,
FROM mytable GROUP BY Status

然后我们有了这个结果

Status    Small    Medium    Large
OK         1         2         1
BAD        2         1         0

获得的正确代码是什么：

Status    Small    Medium    Large
OK         1         2         1
BAD        2         1         0
TOTAL      3         3         1

Answer 1

您可以在WITH ROLLUP条件中添加GROUP BY条款，如下所示：

SELECT
  CASE WHEN CONDITION=1 THEN 'OK' ELSE 'BAD' END AS Status,
  SUM (CASE WHEN SIZE=10 THEN 1 ELSE 0 END) AS Small,
  SUM (CASE WHEN SIZE=20 THEN 1 ELSE 0 END) AS Medium,
  SUM (CASE WHEN SIZE=30 THEN 1 ELSE 0 END) AS Large,
FROM mytable
GROUP BY Status WITH ROLLUP

这将产生如下结果集：

Status    Small    Medium    Large
OK         1         2         1
BAD        2         1         0
[NULL]     3         3         1

您需要了解“状态”列中不存在任何Total值的行为。相反，“状态”列将具有NULL值，表示这是汇总的位置。

有关详细信息，请参阅此处的文档：http://dev.mysql.com/doc/refman/5.6/en/group-by-modifiers.html

Answer 2

如果我理解正确，你需要在一个完整的查询中使用union，因为你不能同时以不同的方式聚合。

SELECT
  CASE WHEN CONDITION=1 THEN 'OK' ELSE 'BAD' END AS Status,
  SUM (CASE WHEN SIZE=10 THEN 1 ELSE 0 END) AS Small,
  SUM (CASE WHEN SIZE=20 THEN 1 ELSE 0 END) AS Medium,
  SUM (CASE WHEN SIZE=30 THEN 1 ELSE 0 END) AS Large,
FROM mytable GROUP BY Status

UNION

SELECT
  'Total' AS Status,
  SUM (CASE WHEN SIZE=10 THEN 1 ELSE 0 END) AS Small,
  SUM (CASE WHEN SIZE=20 THEN 1 ELSE 0 END) AS Medium,
  SUM (CASE WHEN SIZE=30 THEN 1 ELSE 0 END) AS Large,
FROM mytable

在Mysql中对来自不同条件的行求和

2 个答案: