• [转]几种常见SQL分页方式


    创建环境:

    create table pagetest
    (
    id int identity(1,1) not null,
    col01 int null,
    col02 nvarchar(50) null,
    col03 datetime null
    )
    
    --100万记录集(大约耗时5min)
    declare @i int
    set @i=0
    while(@i<1000000)
    begin
        insert into pagetest select cast(floor(rand()*10000) as int),left(newid(),10),getdate()
        set @i=@i+1
    end

    几种分页方式比较:

    --写法1,not in/top
    --每页50条,取第2015页数据
    declare @begin_date datetime
    declare @end_date datetime
    select @begin_date = getdate()
    select top 50 * from pagetest 
    where id not in (select top ((2015-1)*50) id from pagetest order by id)
    order by id
    select @end_date = getdate()
    select datediff(ms,@begin_date,@end_date) as 'ms'

    结果:473 ms

    --写法2,not exists
    declare @begin_date datetime
    declare @end_date datetime
    select @begin_date = getdate()
    select top 50 * from pagetest 
    where not exists 
    (select 1 from (select top ((2015-1)*50) id from pagetest order by id)a  where a.id=pagetest.id)
    order by id
    select @end_date = getdate()
    select datediff(ms,@begin_date,@end_date) as 'ms'

    结果:483 ms

    --写法3,max/top
    declare @begin_date datetime
    declare @end_date datetime
    select @begin_date = getdate()
    select top 50 * from pagetest
    where id>(select max(id) from (select top ((2015-1)*50) id from pagetest order by id)a)
    order by id
    select @end_date = getdate()
    select datediff(ms,@begin_date,@end_date) as 'ms'

    结果:343 ms

    --写法4,row_number() 只支持sql2005及以上版本
    declare @begin_date datetime
    declare @end_date datetime
    select @begin_date = getdate()
    select top 50 * from 
    (select row_number()over(order by id)rownumber,* from pagetest)a
    where rownumber>((2015-1)*50)
    select @end_date = getdate()
    select datediff(ms,@begin_date,@end_date) as 'ms'

    结果:293 ms

    以上测试在不同环境在会有略微差别,整体来说都还不错,row_number和max/top方式性能相对更好些,而row_number只支持sql2005版本及以上,所以max/top在大部分环境下会是比较好的选择。

    简单将ROWNUMBER,max/top的方式封装到存储过程。

    create proc [dbo].[spSqlPageByRownumber]
    @tbName varchar(255),        --表名
    @tbFields varchar(1000),      --返回字段(可以为*)
    @PageSize int,                --页尺寸
    @PageIndex int,                --页码
    @strWhere varchar(1000),    --查询条件(为空则无条件)
    @StrOrder varchar(255),  --排序条件
    @Total int output            --返回总记录数
    as
    declare @strSql varchar(5000)    --主语句
    declare @strSqlCount nvarchar(500)--查询记录总数主语句
    
    --------------总记录数---------------
    if @strWhere !=''
    begin
    set @strSqlCount='Select @TotalCout=count(*) from  ' + @tbName + ' where '+ @strWhere
    end
    else
    begin
    set @strSqlCount='Select @TotalCout=count(*) from  ' + @tbName
    end
    --------------分页------------
    if @PageIndex <= 0
    begin
      set @PageIndex = 1
    end
    
    set @strSql='Select * from (Select  row_number() over('+@strOrder+') rowId,'+ @tbFields
    +' from ' + @tbName + ' where 1=1 ' + @strWhere+' ) tb where tb.rowId >'+str((@PageIndex-1)*@PageSize)
    +' and tb.rowId <= ' +str(@PageIndex*@PageSize)
    
    exec sp_executesql @strSqlCount,N'@TotalCout int output',@Total output
    exec(@strSql)
    create proc [dbo].[spSqlPageByMaxTop]
    @tbName varchar(255),        --表名
    @tbFields varchar(1000),      --返回字段(可以为*)
    @PageSize int,                --页尺寸
    @PageIndex int,                --页码
    @strWhere varchar(1000),    --查询条件(为空则无条件)
    @StrOrder varchar(255),  --排序条件
    @Total int output            --返回总记录数
    as
    declare @strSql varchar(5000)    --主语句
    declare @strSqlCount nvarchar(500)--查询记录总数主语句
    
    --------------总记录数---------------
    if @strWhere !=''
    begin
    set @strSqlCount='Select @TotalCout=count(*) from  ' + @tbName + ' where '+ @strWhere
    end
    else
    begin
    set @strSqlCount='Select @TotalCout=count(*) from  ' + @tbName
    end
    --------------分页------------
    if @PageIndex <= 0
    begin
      set @PageIndex = 1
    end
    
    set @strSql='select top '+str(@PageSize)+' * from ' + @tbName + '
    where id>(select max(id) from (select top '+str((@PageIndex-1)*@PageSize)+' id from ' + @tbName + ''+@strOrder+')a)
    '+@strOrder+''
    
    exec sp_executesql @strSqlCount,N'@TotalCout int output',@Total output
    exec(@strSql)

    转载自:http://www.cnblogs.com/iamowen/archive/2011/11/03/2235068.html

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  • 原文地址:https://www.cnblogs.com/xiepeixing/p/4329340.html
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