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【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 @t1        SELECT  1 ,                 ,                7        UNION ALL        SELECT  2 ,                 ,                8        UNION ALL        SELECT  3 ,                 ,                8        UNION ALL        SELECT  4 ,                 ,                8        UNION ALL        SELECT  5 ,                 ,                9        UNION ALL        SELECT  1 ,                 ,                10        UNION ALL        SELECT  2 ,                 ,                6        UNION ALL        SELECT  3 ,                 ,                10        UNION ALL        SELECT  4 ,                 ,                6        UNION ALL        SELECT  5 ,                 ,                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 BucketFROM    @t1

结果集:

【T-SQL系列】新的排序函数