TSQL 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：

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： 

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：