SQL SERVER 分页

SQL SERVER2012在ORDER BY 子句中加入了新元素offset,允许用户在排序完成的结果集中自定义输出行范围，大大简化了分页SQL的书写方式和效率。以下是与以前的两种分页方式的简单对比

SQL code

    
    
    
    

     
     
     
     use
     
     
     
      master 
     
     
     
     go
     
     
     
      
     
     
     
     set
     
     
     
      nocount 
     
     
     
     on
     
     
     
      
     
     
     
     go
     
     
     
      
     
     
     
     set
     
     
     
      showplan_text 
     
     
     
     on
     
     
     
      
     
     
     
     go
     
     
     
      
     
     
     
     --
     
     
     
     2012的OFFSET分页方式
     
     
     
      
     
     
     
     select
     
     
     
      
     
     
     
     number
     
     
     
      
     
     
     
     from
     
     
     
      spt_values 
     
     
     
     where
     
     
     
      type
     
     
     
     =
     
     
     
     '
     
     
     
     p
     
     
     
     '
     
     
     
      
     
     
     
     order
     
     
     
      
     
     
     
     by
     
     
     
      
     
     
     
     number
     
     
     
      offset 
     
     
     
     10
     
     
     
      rows 
     
     
     
     fetch
     
     
     
      
     
     
     
     next
     
     
     
      
     
     
     
     5
     
     
     
      rows 
     
     
     
     only
     
     
     
     ; 
     
     
     
     go
     
     
     
      
     
     
     
     --
     
     
     
     2005的ROW_NUMBER分页方式
     
     
     
      
     
     
     
     select
     
     
     
      
     
     
     
     number
     
     
     
      
     
     
     
     from
     
     
     
      ( 
     
     
     
     select
     
     
     
      
     
     
     
     number
     
     
     
     ,row_number() 
     
     
     
     over
     
     
     
     (
     
     
     
     order
     
     
     
      
     
     
     
     by
     
     
     
      
     
     
     
     number
     
     
     
     ) 
     
     
     
     as
     
     
     
      num 
     
     
     
     from
     
     
     
      spt_values 
     
     
     
     where
     
     
     
      type
     
     
     
     =
     
     
     
     '
     
     
     
     p
     
     
     
     '
     
     
     
      ) t 
     
     
     
     where
     
     
     
      num 
     
     
     
     between
     
     
     
      
     
     
     
     11
     
     
     
      
     
     
     
     and
     
     
     
      
     
     
     
     15
     
     
     
      
     
     
     
     order
     
     
     
      
     
     
     
     by
     
     
     
      
     
     
     
     number
     
     
     
      
     
     
     
     asc
     
     
     
      
     
     
     
     go
     
     
     
      
     
     
     
     --
     
     
     
     2000的TOP分页方式
     
     
     
      
     
     
     
     select
     
     
     
      
     
     
     
     number
     
     
     
      
     
     
     
     from
     
     
     
      ( 
     
     
     
     select
     
     
     
      
     
     
     
     top
     
     
     
      
     
     
     
     5
     
     
     
      
     
     
     
     number
     
     
     
      
     
     
     
     from
     
     
     
      ( 
     
     
     
     select
     
     
     
      
     
     
     
     top
     
     
     
      
     
     
     
     15
     
     
     
      
     
     
     
     number
     
     
     
      
     
     
     
     from
     
     
     
      spt_values 
     
     
     
     where
     
     
     
      type
     
     
     
     =
     
     
     
     '
     
     
     
     p
     
     
     
     '
     
     
     
      
     
     
     
     order
     
     
     
      
     
     
     
     by
     
     
     
      
     
     
     
     number
     
     
     
      
     
     
     
     asc
     
     
     
      ) t 
     
     
     
     order
     
     
     
      
     
     
     
     by
     
     
     
      
     
     
     
     number
     
     
     
      
     
     
     
     desc
     
     
     
      ) t 
     
     
     
     order
     
     
     
      
     
     
     
     by
     
     
     
      
     
     
     
     number
     
     
     
      
     
     
     
     asc
     
     
     
      
     
     
     
     go
     
     
     
      
     
     
     
     set
     
     
     
      showplan_text 
     
     
     
     off
     
     
     
      
     
     
     
     go
     
     
     
      
     
     
     
     /*
     
     
     
      StmtText ---------------------------------------------------------------------------------------------------------- select number from spt_values where type='p' order by number offset 10 rows fetch next 5 rows only; StmtText -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |--Top(OFFSET EXPRESSION:((10)),TOP EXPRESSION:((5))) |--Index Scan(OBJECT:([mssqlsystemresource].[sys].[spt_values].[ix2_spt_values_nu_nc]), WHERE:(CONVERT(nchar(3),[mssqlsystemresource].[sys].[spt_values].[type],0)=N'p') ORDERED FORWARD) StmtText --------------------------------------------------------------------------------------------------------------------------------------------------------------------- select number from ( select number,row_number() over(order by number) as num from spt_values where type='p' ) t where num between 11 and 15 order by number asc StmtText ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |--Sort(ORDER BY:([mssqlsystemresource].[sys].[spt_values].[number] ASC)) |--Filter(WHERE:([Expr1005]>=(11) AND [Expr1005]<=(15))) |--Top(TOP EXPRESSION:(CASE WHEN (15) IS NULL OR (15)<(0) THEN (0) ELSE (15) END)) |--Sequence Project(DEFINE:([Expr1005]=row_number)) |--Segment |--Index Scan(OBJECT:([mssqlsystemresource].[sys].[spt_values].[ix2_spt_values_nu_nc]), WHERE:(CONVERT(nchar(3),[mssqlsystemresource].[sys].[spt_values].[type],0)=N'p') ORDERED FORWARD) StmtText ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- select number from ( select top 5 number from ( select top 15 number from spt_values where type='p' order by number asc ) t order by number desc ) t order by number asc StmtText ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |--Sort(ORDER BY:([mssqlsystemresource].[sys].[spt_values].[number] ASC)) |--Sort(TOP 5, ORDER BY:([mssqlsystemresource].[sys].[spt_values].[number] DESC)) |--Top(TOP EXPRESSION:((15))) |--Index Scan(OBJECT:([mssqlsystemresource].[sys].[spt_values].[ix2_spt_values_nu_nc]), WHERE:(CONVERT(nchar(3),[mssqlsystemresource].[sys].[spt_values].[type],0)=N'p') ORDERED FORWARD) 
     
     
     
     */
    
    
    
    

从查询计划来看，2012的查询计划中，offset直接操作了top迭代器，分页计划十分简单，看起来也比后两种简单明了。
而在系统预估的查询开销中，OFFSET占9%，ROW_NUMBER占45%，TOP占47%（加起来101% -_-||）,OFFSET占了绝对的优势。

在2008的更新中，我最喜欢的是MERGE，2012中就是OFFSET了。