小编典典

SQL Server-遇到0时重置的累积总和

sql

我想对列进行累加,但是每当遇到0时就重置聚合值

这是我尝试做的一个例子:

该数据集:

pk    price
1     10
2     15
3     0
4     10
5     5

给出以下内容:

pk    price
1     10
2     25
3     0
4     10 
5     15

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2021-03-23

共1个答案

小编典典

在SQL Server 2008中,由于无法使用分析函数,因此受到了严重限制。以下方法效率不高,但可以解决您的问题:

with tg as (
      select t.*, g.grp
      from t cross apply
           (select count(*) as grp
            from t t2
            where t2.pk <= t.pk and t2.pk = 0
           ) g
     )
select tg.*, p.running_price
from tg cross apply
     (select sum(tg2.price) as running_price
      from tg tg2
      where tg2.grp = tg.grp and tg2.pk <= tg.pk
     ) p;

las,在SQL Server 2012之前,最有效的解决方案可能涉及游标。在SQL Server 2012+中,您只需执行以下操作:

select t.*,
       sum(price) over (partition by grp order by pk) as running_price
from (select t.*,
             sum(case when price = 0 then 1 else 0 end) over (order by pk) as grp
      from t
     ) t;
2021-03-23