如何从结果集中获取最后一行的值，并将其与结果集中的下一组行相加 [英] how to get the last row value from resultset and add it with next set of rows in the resultset

问题描述

大家好，

我如何在sql server中实现以下逻辑:

我在表中有3列说:

Hi all,

How can i implement this following logic in sql server :

I have 3 columns in a table say :

Distance  Height   Sequence
0.91      10        1
0.98      11        1
1.2       12        1
0         13        2
0.81      15        2
0.98      17        2
1.6       19        3
2.1       19.5      3

逻辑如下:
我应该将偏移值设置为0.0
当新序列开始时，我应该在先前的行序列值上加上偏移值

例如:
设置offset = 0.0
偏移量= 0.0 + 1.2(上一行值)= 1.2

我应该为序列号为2的值添加上述偏移值.
具有2的序列的输出将是:

logic is as follows:
i should set offset value as 0.0
when new sequence starts, i should add offset value with previous row sequence value

eg:
set offset=0.0
offset=0.0+1.2(previous row value)=1.2

i should add the above offset value for values having sequence numbers as 2.
output for sequence having 2 will be :

Distance  Height   Sequence
1.2       13        2
2.01      15        2
2.18      17        2

现在offset = 1.2 + 2.18(上一行值)= 3.38
以上偏移值，我应该添加序列号为3

now offset=1.2+2.18(previous row value)=3.38
above offset value, i should add for sequence numbers as 3

Distance  Height   Sequence
4.98       19        3
5.48       19.5      3

总的来说，我的表应该返回以下输出:

Overall my table should return the following output :

Distance  Height   Sequence
0.91      10        1
0.98      11        1
1.2       12        1
1.2       13        2
2.01      15        2
2.18      17        2
4.98      19        3
5.48      19.5      3

在此先谢谢您.

Thanks in advance.

推荐答案

您是否正在寻找递归CTE?

http://msdn.microsoft.com/zh-cn/library/ms186243(v = sql.105).aspx

are you looking for a recursive CTE?

http://msdn.microsoft.com/en-us/library/ms186243(v=sql.105).aspx

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