将负累积总和设置为零有人可以建议最好的方法吗？ [复制]

Question

我有一个包含负值和正值的金额列的表。我想计算值的总和并将负累积总和设置为零。

date        amount  actu_cusum  exp_cusum
22-06-2018  60.626   60.626      60.626
29-06-2018  -78.309 -17.683       0
02-07-2018  -0.824  -18.507       0
09-07-2018  -0.822  -19.329       0
10-07-2018  14.79   -4.539       14.79
29-07-2018  20      15.461       34.79
30-07-2018  -30     -24.539      4.79
31-07-2018  15      -9.539       19.79


update a set a.calamount= z.cusum
from #temp a, 
( select CustomerCode,  date ,amount, 
SUM(totaumamount) over ( partition by CustomerCode order by date )
as cusum from #temp
) z
where a.customercode = z.customercode and a.date = z.date

Answer 1

（您的问题中缺少列和表） 您可以使用：

... set a.calamount = case when z.cusum < 0 then 0 else z.cusum end ...

编辑：对于个别负值：

update a set a.calamount= z.cusum
from #temp a, 
( select CustomerCode,  date ,amount, 
SUM(case when totaumamount < 0 then 0 else totaumamount end) over ( partition by CustomerCode order by date )
as cusum from #temp
) z
where a.customercode = z.customercode and a.date = z.date