当前行的值+前几行的总和

问题描述

如何从中转换表中的列:

How would you do to transform a Column in a table from this:

ColumnA   ColumnB
2           a
3           b
4           c
5           d
1           a

对此:

ColumnA          ColumnB
3                 a
6(=3+3)           b   
10(=4+3+3)        c   
15(=5+4+3+3)      d 

我有兴趣见到esp.您会选择哪种方法.

I'm interested to see esp. what method you would pick.

推荐答案

像这样:

;WITH cte
AS
(
   SELECT ColumnB, SUM(ColumnA) asum 
   FROM @t 
   gROUP BY ColumnB

), cteRanked AS
(
   SELECT asum, ColumnB, ROW_NUMBER() OVER(ORDER BY ColumnB) rownum
   FROM cte
) 
SELECT (SELECT SUM(asum) FROM cteRanked c2 WHERE c2.rownum <= c1.rownum),
  ColumnB
FROM cteRanked c1;

这应该给您:

ColumnA    ColumnB
3             a
6             b
10            c
15            d

这篇关于当前行的值+前几行的总和的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！