|
/*
名称:spAll_ReturnRows
输入:
输出:
调用:
EXEC spAll_ReturnRows 'select * FROM 表名', 页号, 返回记录数, '主键', '排序字段'
spAll_ReturnRows 'select * FROM all_Categories',2,10,'[ID]','[ID]'
说明:[百万级]通用存储过程.分页存储过程..返回指定返回条数、指定页数的记录
作者:Dili J.F. Senders
邮件:diliatwellknow.net
更新:20040610
版权:转述时请注明来源:用思维创造未来的Wellknow.net
*/
create PROCEDURE dbo.spAll_ReturnRows
(
@SQL nVARCHAR(4000),
@Page int,
@RecsPerPage int,
@ID VARCHAR(255),
@Sort VARCHAR(255)
)
AS
DECLARE @Str nVARCHAR(4000)
SET @Str='select TOP '+cast(@RecsPerPage AS VARCHAR(20))+' * FROM ('+@SQL+') T where T.'+@ID+' NOT IN
(select TOP '+cast((@RecsPerPage*(@Page-1)) AS VARCHAR(20))+' '+@ID+' FROM ('+@SQL+') T9 ORDER BY '+@Sort+') ORDER BY '+@Sort
PRINT @Str
EXEC sp_ExecuteSql @Str
GO
/*
名称:spAll_deleteNoneUnique
输入:要查询的表名和字段列表
输出:
调用:
说明:实现千万级数据的分页显示!--可以在5秒内获取1448万条记录里的第1200页的100条记录，雄不？
作者:铁拳版权:转述时请注明来源:用思维创造未来的Wellknow.net
*/
create PROCEDURE GetRecordFromPage
@tblName varchar(255), -- 表名
@fldName varchar(255), -- 字段名
@PageSize int = 10, -- 页尺寸
@PageIndex int = 1, -- 页码
@IsCount bit = 0, -- 返回记录总数, 非 0 值则返回
@OrderType bit = 0, -- 设置排序类型, 非 0 值则降序
@strwhere varchar(1000) = '' -- 查询条件 (注意: 不要加 where)
AS
declare @strSQL varchar(6000) -- 主语句
declare @strTmp varchar(100) -- 临时变量
declare @strOrder varchar(400) -- 排序类型
if @OrderType != 0
begin
set @strTmp = "<(select min"
set @strOrder = " order by [" + @fldName +"] desc"
end
else
begin
set @strTmp = ">(select max"
set @strOrder = " order by [" + @fldName +"] asc"
end
set @strSQL = "select top " + str(@PageSize) + " * from ["
+ @tblName + "] where [" + @fldName + "]" + @strTmp + "(["
+ @fldName + "]) from (select top " + str((@PageIndex-1)*@PageSize) + " ["
+ @fldName + "] from [" + @tblName + "]" + @strOrder + ") as tblTmp)"
+ @strOrder
if @strwhere != ''
set @strSQL = "select top " + str(@PageSize) + " * from ["
+ @tblName + "] where [" + @fldName + "]" + @strTmp + "(["
+ @fldName + "]) from (select top " + str((@PageIndex-1)*@PageSize) + " ["
+ @fldName + "] from [" + @tblName + "] where " + @strwhere + " "
+ @strOrder + ") as tblTmp) and " + @strwhere + " " + @strOrder
if @PageIndex = 1
begin
set @strTmp = ""
if @strwhere != ''
set @strTmp = " where " + @strwhere
set @strSQL = "select top " + str(@PageSize) + " * from ["
+ @tblName + "]" + @strTmp + " " + @strOrder
end
if @IsCount != 0
set @strSQL = "select count(*) as Total from [" + @tblName + "]"
exec (@strSQL)
GO
个人研究百万级数据提出问题总结如下：
1.除了提高硬件方面
2.采取折中方法，一次提出几百万数据也没有什么实在意义
不过存储过程写的还是很精妙。
p=pagesize,n为返回页数,SQL="select * from product where id<200000"
1.(select * from product where id<200000) as t
2.(select top p*(n-1) t.id from t order by id asc) as t1
3.select top p * from t where id not in t1 order by id asc
SQL:
select top p * from (select * from product where id<200000) t where t.id not in (select top p*(n-1) id from t order by id asc) order by id asc
[注:子查询里面别名t 其实并不存在，应该用1.重新代替]
SQL存储过程:
SET @str='select top'+cast(@p as varchar(20))+' * from ('+@SQL+') t where t.'+@ID+' not in (select top '+cast((@p*(@n-1)) as varchar(20))+' '+@ID+' from ('+SQL+') order by '+@Sort+') order by '+@Sort
PRINT @str
百万级数据测试结果如下：
//////////////////////////////
///result:100W数据
///
///条件:VirtualItemCount=200000
///->转1页 33.924982085712 milliseconds,33.3696042374101 milliseconds,31.1483722093171 milliseconds
///->转1000页 247.380882207096 milliseconds,190.643224208663 milliseconds,240.085262233049 milliseconds
///->转10000页 2393.90201827327 milliseconds,1903.65535284512 milliseconds,1839.06278591273 milliseconds
///
///条件:VirtualItemCount=all
///->1 10.2540965402027 milliseconds,7.47608983823363 milliseconds,15.5991892824367 milliseconds
///->1000 273.380555349912 milliseconds,190.414982909839 milliseconds,217.308345055028 milliseconds
///->10000 1845.92064075183 milliseconds,1951.84974626663 milliseconds,1904.51831168487 milliseconds
///
///2s处理百万数据
////////////////////////////// |