根据年份列选择上一年数据

Question

我正在尝试开发 SSRS 报告。我从事务表中获取了销售价值，并按年、月和子类别对它们进行了分组。我已将其创建为视图。查看代码如下：

SELECT b.FiscalYear AS Year, 
       b.FiscalMonth AS Month, 
       a.SubCategoryKey, 
       MAX(a.SubCategoryDesc) AS SubCategoryDesc, 
       SUM(CAST(a.Cost + a.FreightCost AS decimal(18, 2))) AS TotalCost, 
       SUM(CAST(a.SalesAmount AS decimal(18, 2))) AS   TotalSales,       
SUM(CAST(a.Weight AS decimal(18, 2))) AS Pounds, SUM(CAST(a.SalesAmount -(a.Cost + a.FreightCost) AS decimal(18, 2))) AS Margin
FROM dbo.GrossMargin_CorrectedCosts AS a 
LEFT OUTER JOIN dbo.M_DateDim AS b ON a.InvoiceDate = b.Date
GROUP BY b.FiscalYear, b.FiscalMonth, a.SubCategoryKey

然后我得到一个干净的视图，如下所示：

SELECT [Year]
  ,[Month]
  ,[SubCategoryKey]
  ,[SubCategoryDesc]
  ,[TotalCost]
  ,[TotalSales]
  ,[Pounds]
  ,[Margin] 
  FROM [FinancialData].[dbo].[SubCategorySalesbyMonth_V]\

我现在想在这个查询中添加额外的列。我将把它作为 SSRS 报告运行，并传递 Year 和 Month 参数。我想做的是，当2017年被选为已通过的年份参数时，我想向Totalsales，Totalcost和Fings显示前一年的值。

而查询看起来像这样：

SELECT [Year]
  ,[Month]
  ,[SubCategoryKey]
  ,[SubCategoryDesc]
  ,[TotalCost]
  ,[TotalSales]
  ,[Pounds]
  ,[Margin]
  ,PreviousYearTotalSales
  ,PreviousYearTotalCost
  ,PreviousYearPounds 
  FROM [FinancialData].[dbo].[SubCategorySalesbyMonth_V] 

基本上，当将年份和月份传递给报告时，我想显示该给定期间减去一年的前几年的总销售额、总成本和磅数。我有时间做这件事。

我觉得我什么都试过了，但显然没有。请帮忙。

Answer 1

现在您可以使用的视图是以下查询。

SELECT CY.[Year]
,CY.[Month]
,CY.[SubCategoryKey]
,CY.[SubCategoryDesc]
,CY.[TotalCost]
,CY.[TotalSales]
,CY.[Pounds]
,CY.[Margin] 
,PY.[TotalSales] AS PreviousYearTotalSales
,PY.[TotalCost] AS PreviousYearTotalCost
,PY.[Pounds] AS PreviousYearPounds 
FROM [FinancialData].[dbo].[SubCategorySalesbyMonth_V] CY LEFT JOIN [FinancialData].[dbo].[SubCategorySalesbyMonth_V] PY
ON CY.[Year] - 1 = PY.[Year]
AND CY.[Month] = PY.[Month]
AND CY.[SubCategoryKey] = PY.[SubCategoryKey]
AND CY.[Month] = PY.[Month]

这只是一个简单的自我左连接到同一个视图，但是从当前年份 (CY) 开始的年份正在加入到上一年 (PY) 的年份 - 1。它是 LEFT JOIN，所以如果没有任何前一年/月的数据可用，前一年的值将为空。

希望这会有所帮助。