【T-SQL系列】新的排序函数

原文:【T-SQL系列】新的排序函数

如：ROW_NUMBER、RANK、DENSE_RANK
三个分析函数都是按照col1分组内从1开始排序

ROW_NUMBER() 是没有重复值的排序(即使两天记录相等也是不重复的)，可以利用它来实现分页
DENSE_RANK() 是连续排序，两个第二名仍然跟着第三名
RANK() 是跳跃拍学，两个第二名下来就是第四名

示例：

DECLARE @t1 TABLE(Sequence INT ,Name VARCHAR(20) ,Score INT)INSERT  INTO @t1SELECT  1 ,'甲' ,7UNION ALLSELECT  2 ,'甲' ,8UNION ALLSELECT  3 ,'甲' ,8UNION ALLSELECT  4 ,'甲' ,8UNION ALLSELECT  5 ,'甲' ,9UNION ALLSELECT  1 ,'乙' ,10UNION ALLSELECT  2 ,'乙' ,6UNION ALLSELECT  3 ,'乙' ,10UNION ALLSELECT  4 ,'乙' ,6UNION ALLSELECT  5 ,'乙' ,8SELECT  Sequence ,Name ,Score ,ROW_NUMBER() OVER ( ORDER BY Sequence, Score ) AS RowNumber1 ,ROW_NUMBER() OVER ( ORDER BY Sequence, Score DESC ) AS RowNumber2 ,RANK() OVER ( ORDER BY Score ) AS Rnk ,DENSE_RANK() OVER ( ORDER BY Score ) AS DenseRnk ,NTILE(15) OVER ( ORDER BY Score ) AS Bucket
FROM    @t1

结果集：