Question

我正在尝试运行以下查询：

Select T, COUNT(T) as CountOf, (COUNT(T)*100)/(SUM(COUNT(T))) AS percen FROM
(
select prod as T, x,y,z from table1
UNION ALL select prod as T, x,y,z from table2
UNION ALL select prod as T, x,y,z from table3
)
AS m
GROUP BY T ORDER BY COUNT(T) DESC;

上述查询给出了错误。我能够在没有第3个参数的情况下成功运行查询，即(COUNT(T)*100)/(SUM(COUNT(T))) AS percent（计算第2个参数的百分比分布，即CountOf）

但是当我包含百分比参数时，它会给出错误。任何有关这方面的帮助将不胜感激。

Answer 1

您需要将SUM更改为SUM OVER，但MySQL不支持此功能：

SELECT T, COUNT(T) AS CountOf, 
   (COUNT(T)*100)/(SUM(COUNT(T)) OVER ()) AS percen
FROM
 (
   SELECT prod AS T, x,y,z FROM table1
   UNION ALL 
   SELECT prod AS T, x,y,z FROM table2
   UNION ALL 
   SELECT prod AS T, x,y,z FROM table3
  ) AS m
GROUP BY T 
ORDER BY COUNT(T) DESC;

Answer 2

我不喜欢使用distinct，但如果您使用的是sql server，可以试试

Select DISTINCT T, COUNT(*) OVER (PARTITION BY T) as CountOf,  ((COUNT(*) OVER (PARTITION BY T) * 100) / COUNT(*) OVER ()) AS percen FROM
(
select prod as T, x,y,z from table1
UNION ALL select prod as T, x,y,z from table2
UNION ALL select prod as T, x,y,z from table3
)
AS m

CTE选项

WITH cteUnion AS (
    SELECT prod AS T, x,y,z FROM table1
    UNION ALL 
    SELECT prod AS T, x,y,z FROM table2
    UNION ALL 
    SELECT prod AS T, x,y,z FROM table3
),
cteUnionWithTotalCount AS (
    SELECT *, COUNT(*) OVER () AS TotalCount FROM cteUnion
)
SELECT  T, COUNT(*) AS CountOf, ((COUNT(*) * 100)/ TotalCount) AS percen
FROM    cteUnionWithTotalCount
GROUP BY T, TotalCount
ORDER BY COUNT(*)

无法嵌套聚合操作

2 个答案: