http://www.cn-web.com/shtml/article/main/2009/07/12/918.shtml
公司一项目数据达到上百万,普通的分页方式满足不了要求,经常发生超时的错误,所以有必要对分页的方式来做下研究。
经过搜集和测试,当前网上的成熟的分页方式有以下几种方案:
分页存储过程1.
此方案只适合单表,中小数据查询,当条件出现in(1,2,3,4,5……)时,则速度明显下降。
分页存储过程2
以下为引用的内容: create PROCEDURE p_qcd_PaginationDichotomy ( @tblName nvarchar(200), ----要显示的表或多个表的连接 @fldName nvarchar(500) = '*', ----要显示的字段列表 @pageSize int = 10, ----每页显示的记录个数 @page int = 1, ----要显示那一页的记录 @fldSort nvarchar(200) = null, ----排序字段列表或条件 @Sort bit = 0, ----排序方法,0为升序,1为降序(如果是多字段排列Sort指代最后一个排序字段的排列顺序(最后一个排序字段不加排序标记)--程序传参如:' SortA Asc,SortB Desc,SortC ') @strCondition nvarchar(1000) = null, ----查询条件,不需where @ID nvarchar(150), ----主表的主键 @Dist bit = 0, ----是否添加查询字段的 DISTINCT 默认0不添加/1添加 @pageCount int = 1 output, ----查询结果分页后的总页数 @Counts int = 1 output ----查询到的记录数 ) AS SET NOCOUNT ON Declare @sqlTmp nvarchar(1000) ----存放动态生成的SQL语句 Declare @strTmp nvarchar(1000) ----存放取得查询结果总数的查询语句 Declare @strID nvarchar(1000) ----存放取得查询开头或结尾ID的查询语句 Declare @strSortType nvarchar(10) ----数据排序规则A Declare @strFSortType nvarchar(10) ----数据排序规则B Declare @SqlSelect nvarchar(50) ----对含有DISTINCT的查询进行SQL构造 Declare @SqlCounts nvarchar(50) ----对含有DISTINCT的总数查询进行SQL构造 declare @timediff datetime --耗时测试时间差 select @timediff=getdate() if @Dist = 0 begin set @SqlSelect = 'select ' set @SqlCounts = 'Count(*)' end else begin set @SqlSelect = 'select distinct ' set @SqlCounts = 'Count(DISTINCT '+@ID+')' end if @Sort=0 begin set @strFSortType=' ASC ' set @strSortType=' DESC ' end else begin set @strFSortType=' DESC ' set @strSortType=' ASC ' end --------生成查询语句cn-web.com提供-------- --此处@strTmp为取得查询结果数量的语句 if @strCondition is null or @strCondition='' --没有设置显示条件 begin set @sqlTmp = @fldName + ' From ' + @tblName set @strTmp = @SqlSelect+' @Counts='+@SqlCounts+' FROM '+@tblName set @strID = ' From ' + @tblName end else begin set @sqlTmp = + @fldName + 'From ' + @tblName + ' where (1>0) ' + @strCondition set @strTmp = @SqlSelect+' @Counts='+@SqlCounts+' FROM '+@tblName + ' where (1>0) ' + @strCondition set @strID = ' From ' + @tblName + ' where (1>0) ' + @strCondition end ----取得查询结果总数量----- exec sp_executesql @strTmp,N'@Counts int out ',@Counts out declare @tmpCounts int if @Counts = 0 set @tmpCounts = 1 else set @tmpCounts = @Counts --取得分页总数 set @pageCount=(@tmpCounts+@pageSize-1)/@pageSize /**//**//**//**当前页大于总页数 取最后一页**/ if @page>@pageCount set @page=@pageCount --/*-----数据分页2分处理-------*/ declare @pageIndex int --总数/页大小 declare @lastcount int --总数%页大小 set @pageIndex = @tmpCounts/@pageSize set @lastcount = @tmpCounts%@pageSize if @lastcount > 0 set @pageIndex = @pageIndex + 1 else set @lastcount = @pagesize --//***显示分页 if @strCondition is null or @strCondition='' --没有设置显示条件 begin if @pageIndex<2 or @page<=@pageIndex / 2 + @pageIndex % 2 --前半部分数据处理 begin if @page=1 set @strTmp=@SqlSelect+' top '+ CAST(@pageSize as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' order by '+ @fldSort +' '+ @strFSortType else begin if @Sort=1 begin set @strTmp=@SqlSelect+' top '+ CAST(@pageSize as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' where '+@ID+' <(select min('+ @ID +') from ('+ @SqlSelect+' top '+ CAST(@pageSize*(@page-1) as Varchar(20)) +' '+ @ID +' from '+@tblName +' order by '+ @fldSort +' '+ @strFSortType+') AS TBMinID)' +' order by '+ @fldSort +' '+ @strFSortType end else begin set @strTmp=@SqlSelect+' top '+ CAST(@pageSize as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' where '+@ID+' >(select max('+ @ID +') from ('+ @SqlSelect+' top '+ CAST(@pageSize*(@page-1) as Varchar(20)) +' '+ @ID +' from '+@tblName +' order by '+ @fldSort +' '+ @strFSortType+') AS TBMinID)' +' order by '+ @fldSort +' '+ @strFSortType end end end else begin set @page = @pageIndex-@page+1 --后半部分数据处理 if @page <= 1 --最后一页数据显示 set @strTmp=@SqlSelect+' * from ('+@SqlSelect+' top '+ CAST(@lastcount as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' order by '+ @fldSort +' '+ @strSortType+') AS TempTB'+' order by '+ @fldSort +' '+ @strFSortType else if @Sort=1 begin set @strTmp=@SqlSelect+' * from ('+@SqlSelect+' top '+ CAST(@pageSize as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' where '+@ID+' >(select max('+ @ID +') from('+ @SqlSelect+' top '+ CAST(@pageSize*(@page-2)+@lastcount as Varchar(20)) +' '+ @ID +' from '+@tblName +' order by '+ @fldSort +' '+ @strSortType+') AS TBMaxID)' +' order by '+ @fldSort +' '+ @strSortType+') AS TempTB'+' order by '+ @fldSort +' '+ @strFSortType end else begin set @strTmp=@SqlSelect+' * from ('+@SqlSelect+' top '+ CAST(@pageSize as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' where '+@ID+' <(select min('+ @ID +') from('+ @SqlSelect+' top '+ CAST(@pageSize*(@page-2)+@lastcount as Varchar(20)) +' '+ @ID +' from '+@tblName +' order by '+ @fldSort +' '+ @strSortType+') AS TBMaxID)' +' order by '+ @fldSort +' '+ @strSortType+') AS TempTB'+' order by '+ @fldSort +' '+ @strFSortType end end end =@pageIndex / 2 + @pageIndex % 2 --前半部分数据处理 begin if @page=1 set @strTmp=@SqlSelect+' top '+ CAST(@pageSize as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' where 1=1 ' + @strCondition + ' order by '+ @fldSort +' '+ @strFSortType else if(@Sort=1) begin set @strTmp=@SqlSelect+' top '+ CAST(@pageSize as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' where '+@ID+' <(select min('+ @ID +') from ('+ @SqlSelect+' top '+ CAST(@pageSize*(@page-1) as Varchar(20)) +' '+ @ID +' from '+@tblName +' where (1=1) ' + @strCondition +' order by '+ @fldSort +' '+ @strFSortType+') AS TBMinID)' +' '+ @strCondition +' order by '+ @fldSort +' '+ @strFSortType end else begin set @strTmp=@SqlSelect+' top '+ CAST(@pageSize as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' where '+@ID+' >(select max('+ @ID +') from ('+ @SqlSelect+' top '+ CAST(@pageSize*(@page-1) as Varchar(20)) +' '+ @ID +' from '+@tblName +' where (1=1) ' + @strCondition +' order by '+ @fldSort +' '+ @strFSortType+') AS TBMinID)' +' '+ @strCondition +' order by '+ @fldSort +' '+ @strFSortType end end else begin set @page = @pageIndex-@page+1 --后半部分数据处理 if @page <= 1 --最后一页数据显示 set @strTmp=@SqlSelect+' * from ('+@SqlSelect+' top '+ CAST(@lastcount as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' where (1=1) '+ @strCondition +' order by '+ @fldSort +' '+ @strSortType+') AS TempTB'+' order by '+ @fldSort +' '+ @strFSortType else if(@Sort=1) set @strTmp=@SqlSelect+' * from ('+@SqlSelect+' top '+ CAST(@pageSize as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' where '+@ID+' >(select max('+ @ID +') from('+ @SqlSelect+' top '+ CAST(@pageSize*(@page-2)+@lastcount as Varchar(20)) +' '+ @ID +' from '+@tblName +' where (1=1) '+ @strCondition +' order by '+ @fldSort +' '+ @strSortType+') AS TBMaxID)' +' '+ @strCondition+' order by '+ @fldSort +' '+ @strSortType+') AS TempTB'+' order by '+ @fldSort +' '+ @strFSortType else set @strTmp=@SqlSelect+' * from ('+@SqlSelect+' top '+ CAST(@pageSize as VARCHAR(4))+' '+ @fldName+' from '+@tblName +' where '+@ID+' <(select min('+ @ID +') from('+ @SqlSelect+' top '+ CAST(@pageSize*(@page-2)+@lastcount as Varchar(20)) +' '+ @ID +' from '+@tblName +' where (1=1) '+ @strCondition +' order by '+ @fldSort +' '+ @strSortType+') AS TBMaxID)' +' '+ @strCondition+' order by '+ @fldSort +' '+ @strSortType+') AS TempTB'+' order by '+ @fldSort +' '+ @strFSortType end end
else --有查询条件 begin if @pageIndex<2 or @page<
------返回查询结果----- --select @pageCount ,@Counts --select @pageCount exec sp_executesql @strTmp select datediff(ms,@timediff,getdate()) as 耗时 --print @strTmp SET NOCOUNT OFF GO
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此分页俗称二分法,执行效率超快,数据量达到百万后效率也没有明显下降,缺点同上,当条件出现in(1,2,3,4,5……)时,则速度明显下降。
分页存储过程3
以下为引用的内容: CREATE procedure p_qcd_Paginationcursor @sql nvarchar(4000), --要执行的sql语句 @currentpage int=1, --要显示的页码 @pagesize int=10, --每页的大小 @pagecount int=0 out, --总页数 @recordCount int=0 out--总记录数 as set nocount on declare @cursor int --cursor 是游标的id
declare @timediff datetime --耗时测试时间差 cn-web.com提供 select @timediff=getdate()
exec sp_cursoropen @cursor output,@sql,@scrollopt=1,@ccopt=1,@rowcount=@pagecount output select @recordCount=@pagecount select @pagecount=ceiling(1.0*@pagecount/@pagesize) ,@currentpage=(@currentpage-1)*@pagesize+1 select @pagecount,@currentpage exec sp_cursorfetch @cursor ,16,@currentpage,@pagesize exec sp_cursorclose @cursor select datediff(ms,@timediff,getdate()) as 耗时 GO
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此方案所说是微软没有公开的游标分页,刚开始怀疑游标分页肯定浪费性能,不过经过详细测试后,发现微软就是微软,不管如何测试,不管条件如何复杂,数据量再大,性能一直保持最强劲。
总结:在没有in(1,2,3,4,5……)之类的条件的查询时,三种方案的性能:方案3=方案2>方案1。当存在复杂条件时,方案3>方案2=方案1。