T-SQL PIVOT 行列转换

前面几个例子：

http://www.cnblogs.com/insus/articles/1969896.html

 http://www.cnblogs.com/insus/articles/1970577.html

http://www.cnblogs.com/insus/articles/1970707.html

全是SQL Server行列转换或是列行转换的相关例子。不过在SQL Server2005版本开始，有一个新的函数PIVOT()可以很轻易实现这些功能。参考下面代码：

View Code

SELECT   [ RId ] , [ 2011-01-23 ] , [ 2011-01-24 ] , [ 2011-01-25 ] , [ 2011-01-26 ]
FROM
(
     SELECT   [ Rid ] , [ DT ] , [ Hits ]   FROM   [ dbo ] . [ RecordHits ]
)  AS  p
PIVOT
(
     SUM ( [ Hits ] )  FOR   [ DT ]   IN  ( [ 2011-01-23 ] , [ 2011-01-24 ] , [ 2011-01-25 ] , [ 2011-01-26 ] )
)  AS  Q;

 

执行结果：

 

另一种是想把上面的结果进行列行转换： 

View Code

SELECT   [ DT ] , [ R1 ] , [ R2 ] , [ R3 ] , [ R4 ]
FROM
(
     SELECT   [ Rid ] , [ DT ] , [ Hits ]   FROM   [ dbo ] . [ RecordHits ]
)  AS  p
PIVOT
(
     SUM ( [ Hits ] )  FOR   [ RId ]   IN  ( [ R1 ] , [ R2 ] , [ R3 ] , [ R4 ] )
)  AS  Q;

 

执行结果：