从每个组中检索列的最后一个元素,并将其用作下一组中同一列的第一个元素

Question

我有一张桌子如下

Domain     Baseline     PlanningPeriod     Actual   
-------------------------------------------------      
Dom 1       Jan 18        1/1/18            10
Dom 1       Jan 18        1/2/18            20
Dom 1       Jan 18        1/3/18            25
Dom 1       Jan 18        1/4/18            24
Dom 1       Feb 18        1/2/18            60
Dom 1       Feb 18        1/3/18            20
Dom 1       Feb 18        1/5/18            40
Dom 1       Feb 18        1/12/18           70
Dom 1       Mar 18        1/3/18            11
Dom 1       Mar 18        1/4/18            12
Dom 1       Mar 18        1/12/18           18
Dom 1       Apr 18        1/4/18            40
Dom 1       Apr 18        1/5/18            25
Dom 1       Apr 18        1/6/18            15
-------------------------------------------------

请注意,也有不同的域名

所以我试图获得一个额外的列comulativeactual按域,基线,计划周期分组.

出于此目的,我做了以下查询

select domain,baseline,planningperiod, actual,sum(actual) over(partition 
by domain, baseline order by domain,baseline,planningperiod) as cumilativeactual

Fortuantely按预期工作,并给出了以下结果

Domain     Baseline     PlanningPeriod     Actual    CumActual 
----------------------------------------------------------------      
Dom 1       Jan 18        1/1/18            10        10
Dom 1       Jan 18        1/2/18            20        30
Dom 1       Jan 18        1/3/18            25        55
Dom 1       Jan 18        1/4/18            24        79
Dom 1       Feb 18        1/2/18            60        60
Dom 1       Feb 18        1/3/18            20        80
Dom 1       Feb 18        1/5/18            40        120
Dom 1       Feb 18        1/12/18           70        190
Dom 1       Mar 18        1/3/18            11        11
Dom 1       Mar 18        1/4/18            12        23
Dom 1       Mar 18        1/12/18           18        31
Dom 1       Apr 18        1/4/18            40        40
Dom 1       Apr 18        1/5/18            25        65
Dom 1       Apr 18        1/6/18            15        80
--------------------------------------------------------

但我的要求有点疯狂.我需要每个组的最后一个元素作为下一组的第一个元素.但该组中的其他值完全如上所述.所以我真的很困惑如何实现这一目标.我不喜欢光标,因为有大约20k的记录.

上述方法应如下工作.

Domain     Baseline     PlanningPeriod     Actual    CumActual 
----------------------------------------------------------------      
Dom 1       Jan 18        1/1/18            10        10
Dom 1       Jan 18        1/2/18            20        30
Dom 1       Jan 18        1/3/18            25        55
Dom 1       Jan 18        1/4/18            24        79
Dom 1       Feb 18        1/2/18            60        **79**
Dom 1       Feb 18        1/3/18            20        80
Dom 1       Feb 18        1/5/18            40        120
Dom 1       Feb 18        1/12/18           70        190
Dom 1       Mar 18        1/3/18            11        **190**
Dom 1       Mar 18        1/4/18            12        23
Dom 1       Mar 18        1/12/18           18        31
Dom 1       Apr 18        1/4/18            40        **31**
Dom 1       Apr 18        1/5/18            25        65
Dom 1       Apr 18        1/6/18            15        80
--------------------------------------------------------

Answer 1

您可以使用CTE和LAG()as

with cte as
(
select domain,
       baseline,
       planningperiod, 
       actual,
       sum(actual) over(partition 
       by domain, baseline order by domain,baseline,planningperiod) as cumilativeactual
from t
)
select domain,
       baseline,
       planningperiod, 
       actual,
       case when actual = cumilativeactual then
            lag(cumilativeactual, 1, 0) over(order by domain,baseline,planningperiod)
            else
            cumilativeactual end as cumilativeactual
from cte

演示