运行总减

Question

我正在尝试使用此代码计算 SQL 中的负运行总计，但它没有给我预期的结果。在 01/2021 日期之后，我想减去每个月的销售额。

select Name, Date, Sales, MinusRunningTotal = B.Sales - SUM(A.sales) 
              OVER (PARTITION BY Name ORDER BY Date)
From TableA A 
Join TableB B on A.ID = B.ID
Where Date > '01/2021'

这就是数据的显示方式

Name Date      Sales    
A    01/2021    10         
A    02/2021    1           
A    03/2021    2           
A    04/2021    3  

这就是我想要实现的目标

Name Date      Sales    MinusRunningTotal
A    01/2021    10         10
A    02/2021    1           9
A    03/2021    2           7
A    04/2021    3           4

Answer 1

如果该数据已存在于包含name、date 和sales 列的表中，请尝试：

SELECT [name],
       [date],
       [sales],
       FIRST_VALUE([sales]) OVER (PARTITION BY [name]
                                      ORDER BY [date]) * 2 
           -   SUM([sales]) OVER (PARTITION BY [name]
                                      ORDER BY [date]
                      ROWS UNBOUNDED PRECEDING) AS minus_running_total                                      
 FROM my_table

sql fiddle

这会计算当前名称的所有先前销售额（包括当前值）

`SUM([sales]) OVER (PARTITION BY [name] 
                        ORDER BY [date]`)

这会计算当前名称的第一个时间值 X 2：

`FIRST_VALUE([sales]) OVER (PARTITION BY [name]
                                ORDER BY [date]) * 2`

所以第一行计算为 (10 x 2) - 10 = 10

第二行是 (10 x 2) - (10 + 1) = 9

第三行是 (10 x 2) - (10 + 1 + 2) = 7

等

Answer 2

select Name, Date, Sales, 
ROW_NUMBER() OVER (PARTITION BY Name ORDER BY Date) as RN into 
#temp2 From table 

select Name, Date, Sales, 
case when rn != 1 
then (select sale from #temp2 where RN = 1) - sum(sales) 
              OVER (PARTITION BY Name ORDER BY Date
              rows between UNBOUNDED PRECEDING and current row) 
          else sales end
From #temp2

Answer 3

我制作了一个表格 sss，其中包含您在第二个代码部分中显示的数据。此查询将给出您想要的结果。如果需要加入其他数据，请在下面称为 xs 的 CTE 中进行。

with
xs as (
    select name, dt, sales, sales tot,
        ROW_NUMBER() over (partition by name order by dt) n
    from sss
    ),
rec as (
    select * from xs where n = 1
    
    union all
    
    select xs.name, xs.dt, xs.sales, rec.tot - xs.sales, xs.n
    from rec
    join xs on rec.name = xs.name
        and xs.n = rec.n + 1
    )
select *
from rec

它是如何工作的：

在 CTE（公用表表达式）xs 中，我们按 dt 升序对与给定名称关联的行编号。

CTE rec 是一个递归查询，首先通过“n = 1”过滤获取与名称关联的组的第一行。这成为输出的第一行。 rec 的第二部分获取后续行，其中新行的 n 等于前一行的 n + 1。通过从前一行 tot 中减去新行的销售额得到所需的运行总计，保留在列 tot 中。