SQL Server使用评估子查询分组的外部查询

Question

我想运行一个将生成聚合结果的查询。 我有以下查询评估价格列和件列以产生一个结果。见下文：

Select Case When [Price]/[PIECES] < 10 Then 'Low Value' 
      Else 
     Case When [Price]/[PIECES] >= 10 Then 'High Value' 
      End 
     End 
AS [High/Low] 
FROM [tbl1] 

然后我想利用上述查询（代从上方在下面查询列的[一块高/低价值]查询中的值）的结果，并且通过聚合数据[高/低按价值]。见下：

SELECT [High/Low Value by Piece], Sum([Pieces]) as Pieces, Sum([Price]) as Price 
FROM [tbl1] 
Group by [High/Low Value by Piece] 
Order by [High/Low Value by Piece] 

Answer 1

您的case语句有太多的语法错误。修好后，你可以直接使用case声明select和group by这样的东西。

SELECT CASE 
     WHEN [Price]/[PIECES] < 10 THEN 'Low Value' 
     WHEN [Price]/[PIECES] >= 10 THEN 'High Value' 
     END   AS [High/Low], 
     Sum([Pieces]) AS Pieces, 
     Sum([Price]) AS Price 
FROM [tbl1] 
GROUP BY CASE 
      WHEN [Price]/[PIECES] < 10 THEN 'Low Value' 
      WHEN [Price]/[PIECES] >= 10 THEN 'High Value' 
      END