SQL Server 行列转换

报表显示需求，查询结果往往需要做一些行列转换或列行转换来显示。

就以http://www.cnblogs.com/insus/articles/1968148.html这个例子的数据源做演示。

正常查询结果显示和执行结果，如下：

SELECT   [ RId ] , [ DT ] , [ Hits ]   FROM   [ dbo ] . [ RecordHits ]

 

 

下面演示，把[RId]和[DT]作为列显示：

View Code

SELECT   [ RID ] ,
SUM ( CASE   WHEN   [ DT ]   =   ' 2011-01-23 '   THEN   [ Hits ]   END )  AS   ' 2011-01-23 ' ,
SUM ( CASE   WHEN   [ DT ]   =   ' 2011-01-24 '   THEN   [ Hits ]   END )  AS   ' 2011-01-24 ' ,
SUM ( CASE   WHEN   [ DT ]   =   ' 2011-01-25 '   THEN   [ Hits ]   END )  AS   ' 2011-01-25 ' ,
SUM ( CASE   WHEN   [ DT ]   =   ' 2011-01-26 '   THEN   [ Hits ]   END )  AS   ' 2011-01-26 '
FROM   [ dbo ] . [ RecordHits ]  
GROUP   BY   [ RId ]

 

执行结果：

 

下面把DT,记录[RId]作为列显示：

View Code

SELECT   [ DT ] ,
SUM ( CASE   WHEN   [ RId ]   =   ' R1 '   THEN   [ Hits ]   END )  AS   ' R1 ' ,
SUM ( CASE   WHEN   [ RId ]   =   ' R2 '   THEN   [ Hits ]   END )  AS   ' R2 ' ,
SUM ( CASE   WHEN   [ RId ]   =   ' R3 '   THEN   [ Hits ]   END )  AS   ' R3 ' ,
SUM ( CASE   WHEN   [ RId ]   =   ' R4 '   THEN   [ Hits ]   END )  AS   ' R4 '
FROM   [ dbo ] . [ RecordHits ]  
GROUP   BY   [ DT ]

 

执行显示结果：