Question

我使用group by function和count（*）：

在表上进行操作

SELECT TOP 10000 
  [column1]
  ,[column2]
  ,[column3]
  ,count(*) as counts
FROM TableX
group by column1, column2,column3

我的结果是看起来的表：

column1 | column2 | column2 | Counts
------------------------------------        
   X1   |    X2   |    X3   |   X4
   X5   |    X6   |    X7   |   X8
   ...

现在我如何添加一个额外的列来显示X3 * X4，X7 * X8等的结果？

Answer 1

如果它实际上是SQL-Server而不是MySQL，您可以使用以下内容：

WITH CTE AS
(
    SELECT TOP 10000 
       [column1]
      ,[column2]
      ,[column3]
      ,counts = count(*)  OVER (PARTITION BY column1, column2,column3)
      ,RN = row_number(*) OVER (PARTITION BY column1, column2,column3 Order By column1, column2,column3)
    FROM TableX
)
SELECT  [column1]
       ,[column2]
       ,[column3]
       ,counts
       ,Product1 = column3 * counts, 
       ...
FROM CTE
WHERE RN = 1

Answer 2

使用查询结果，然后乘以：

select  [column1], [column2], [column3], counts, [column3] * counts
from
(
SELECT TOP 10000 
  [column1]
  ,[column2]
  ,[column3]
  ,count(*) as counts
FROM TableX
group by column1, column2,column3
)

将两列乘以第三列，其中一列在sql中为count（*）

2 个答案: