数据透视表中的SQL滚动日期（月）列

Question

我正在制作一份滚动 36个月的销售历史报告。

我现在有什么：

select 
"ItemTable"."ItemNum" 
, [1] MM01 
, [2] MM02 
, [3] MM03 
, ... 
from ( 
select 
"ItemTable"."ItemNum" 
, DateDiff(m, "SalesTable"."SalesDate", GetDate()) months_ago 
, "SalesTable"."SalesQty" - "SalesTable"."ReturnsQty" NetQty 
from your_table 
) as source 
pivot 
( 
sum(NetQty) For months_ago in ([1], [2], [3], ...) 
) as PivotTable 

以下是比较我的（与上面的代码）和我想要的内容的图片：

如何更改此内容以获得我想要的内容？

Answer 1

您似乎使用datediff来获取自销售日期以来的月数，但您可以在销售日期列中执行动态调整。这是代码：

DECLARE @cols AS NVARCHAR(MAX),
        @query  AS NVARCHAR(MAX)

select @cols = STUFF(
        (SELECT distinct ',['+datename(mm,SalesTable.SalesDate)+' of '+datename(year,SalesTable.SalesDate)+']' AS months_ago
              FROM your_table 
        FOR XML PATH(''), TYPE
        ).value('.', 'NVARCHAR(MAX)') 
    ,1,1,'')


set @query = 'SELECT ItemNum, ' + @cols + ' 
from ( select 
       ItemTable.ItemNum, 
       datename(mm,SalesTable.SalesDate)+'' of ''+datename(year,SalesTable.SalesDate)AS months_ago, SalesTable.SalesQty - SalesTable.ReturnsQty AS NetQty 
       from your_table 
) as source 
pivot 
( 
sum(NetQty) For months_ago  in (' + @cols + ')
) as PivotTable'

execute sp_executesql @query;