Question

我有一个查询可以提供36个月的单位销售历史记录。它按原样工作，但我想知道是否有办法让它不那么冗长和繁琐。

查询有两个部分 - 标题和数据。

以下是标题的内容：

SELECT  
DATEADD(m, -36, GETDATE()-day(GETDATE()-1)) AS  "MM36"
, DATEADD(m, -35, GETDATE()-day(GETDATE()-1)) AS  "MM35"
, DATEADD(m, -34, GETDATE()-day(GETDATE()-1)) AS  "MM34"

截至今天，这是2011年9月 - 11月。它继续......

, DATEADD(m, -03, GETDATE()-day(GETDATE()-1)) AS  "MM03"
, DATEADD(m, -02, GETDATE()-day(GETDATE()-1)) AS  "MM02"
, DATEADD(m, -01, GETDATE()-day(GETDATE()-1)) AS  "MM01"

2014年6月 - 8月.36行代码。

提取单位销售数据的陈述如下：

, SUM (CASE WHEN "SalesTable"."SalesDate" BETWEEN DATEADD(m, -36, GETDATE()-day(GETDATE()-1)) AND DATEADD(m, -35, GETDATE()-day(GETDATE()-1))-1 THEN "SalesTable"."SalesQty" - "SalesTable"."ReturnsQty"  ELSE NULL END) AS "NetQty36"
 , SUM (CASE WHEN "SalesTable"."SalesDate" BETWEEN DATEADD(m, -35, GETDATE()-day(GETDATE()-1)) AND DATEADD(m, -34, GETDATE()-day(GETDATE()-1))-1 THEN "SalesTable"."SalesQty" - "SalesTable"."ReturnsQty" ELSE NULL END) AS "NetQty35"
 , SUM (CASE WHEN "SalesTable"."SalesDate" BETWEEN DATEADD(m, -34, GETDATE()-day(GETDATE()-1)) AND DATEADD(m, -33, GETDATE()-day(GETDATE()-1))-1 THEN "SalesTable"."SalesQty" - "SalesTable"."ReturnsQty" ELSE NULL END) AS "NetQty34"

截至今天，这是2011年9月 - 11月。它继续......

 , SUM (CASE WHEN "SalesTable"."SalesDate" BETWEEN DATEADD(m, -03, GETDATE()-day(GETDATE()-1)) AND DATEADD(m, -02, GETDATE()-day(GETDATE()-1))-1 THEN "SalesTable"."SalesQty" - "SalesTable"."ReturnsQty" ELSE NULL END) AS "NetQty03"
 , SUM (CASE WHEN "SalesTable"."SalesDate" BETWEEN DATEADD(m, -02, GETDATE()-day(GETDATE()-1)) AND DATEADD(m, -01, GETDATE()-day(GETDATE()-1))-1 THEN "SalesTable"."SalesQty" - "SalesTable"."ReturnsQty" ELSE NULL END) AS "NetQty02"
 , SUM (CASE WHEN "SalesTable"."SalesDate" BETWEEN DATEADD(m, -01, GETDATE()-day(GETDATE()-1)) AND DATEADD(m, -00, GETDATE()-day(GETDATE()-1))-1 THEN "SalesTable"."SalesQty" - "SalesTable"."ReturnsQty" ELSE NULL END) AS "NetQty01"

2014年6月至8月。

在本报告完成之前，我还有很多要补充的内容，所以我希望尽可能保持整洁。

谢谢，

修改

下面的例子显示，通过上面的代码，我能够得到我想要的东西（没有代表发布图像所以我必须做一个链接）。它还显示，使用数据透视表我错过了我的项目编号和滚动月份。如何添加这两件事？

Example

我尝试删除“ItemTable”。“ItemNum”字段如下，但它没有显示在我的Crystal Report中。我试图把它放在其他任何地方，我得到“无法绑定”的错误。

select 
[0] MM00
, [1] MM01
, [2] MM02
, ...
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 ([0], [1], [2], [3], ...)
) as PivotTable

再次感谢。

Answer 1

这种情况似乎已成熟Pivot table。

的内容

select 
    [0] MM00
  , [1] MM01
  , [2] MM02
  , ...
from (
  select 
      DateDiff(m, "SalesTable"."SalesDate", GetDate()) months_ago
    , "SalesTable"."SalesQty" - "SalesTable"."ReturnsQty" NetQty
  from your_table
) as source
pivot 
(
  sum(NetQty) For months_ago in ([0], [1], [2], [3], ...)
) as PivotTable

修改

完善示例：包括项目编号非常简单;只需将它包含在select语句中即可。

select "ItemTable"."ItemNum" , [0] MM00 , [1] MM01 , [2] MM02 , ... 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 ([0], [1], [2], [3], ...) ) as PivotTable

拥有枢轴列的动态名称相当困难。一般的想法是你必须将SQL构建为字符串并动态执行它。 Google搜索会产生大量结果（例如a SQL Hints blog）。一些不完整的代码可以为您提供一般性的想法。

SET @DynamicPivotQuery = N'select "ItemTable"."ItemNum" , [' + @Name1 + '] , [' + @Name2 + '] , [' + @NameN + '] from ( select "ItemTable"."ItemNum" /* search MSDN for the best date formatting algorithm */ , CONVERT_TO_STRING("SalesTable"."SalesDate") month , "SalesTable"."SalesQty" - "SalesTable"."ReturnsQty" NetQty from your_table ) as source pivot ( sum(NetQty) For month in ( [' + @Name1 + '] , [' + @Name2 + '] , [' + @NameN + '] ) ) as PivotTable'; --Execute the Dynamic Pivot Query EXEC sp_executesql @DynamicPivotQuery

简化SQL SELECT语句？

1 个答案: