请问如何提高该存储过程的执行效率
上次我提问的是联接查询，查询是查询出来了，但是执行还是有3s左右的停顿才显示出数据，我现在用的是建立临时表的办法，数据也查出了，感觉上么，好像也快了点，想问下，在原来的基础上哈能优化吗？？？？

USE [GQ-QiaoYing]
GO
/****** Object: StoredProcedure [dbo].[SelectLastData] Script Date: 07/08/2012 08:14:08 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER proc [dbo].[SelectLastData]

as
create table #tempLastdata
(SiteID int,
 SiteName varchar(50),
 ShuiWei varchar(50),
 LiuLiang varchar(50),
 LiuLiang_Total varchar(50),
 YuLiang varchar(50),
 MYL varchar(50),
 YYL varchar(50),
 date_time datetime )
 
 declare @SiteID varchar(50),
@SiteName varchar(50),
 @ShuiWei varchar(50),
 @LiuLiang varchar(50),
 @LiuLiang_Total varchar(50),
 @YuLiang varchar(50),
 @MYL varchar(50),
 @YYL varchar(50),
 @date_time datetime,
 @Month varchar(50),
 @Year varchar(50),
 @SelectIndex int,
 @count int
 
 select @count=COUNT(*) from LastData
 set @SelectIndex=1
 
 Select @Month=MAX(CONVERT(varchar(7),date_time,120)),@Year=MAX(CONVERT(varchar(4),date_time,120)) from HistoryData
  while @SelectIndex<=@count
 begin
 select @MYL=SUM(Yuliang)from HistoryData where Date_Time >= @Month+'-01' and SiteID=@SelectIndex
 select @YYL=SUM(Yuliang)from HistoryData where Date_Time >= @Year+'-01-01' and SiteID=@SelectIndex
 select @ShuiWei=ShuiWei,@LiuLiang=LiuLiang,@LiuLiang_Total=LiuLiang_Total,@YuLiang=YuLiang,@date_time=Date_Time
  from LastData where SiteID=@SelectIndex order by SiteID
 select @SiteName=SiteName from SiteInfo where SiteID=@SelectIndex order by SiteID
 insert into #tempLastdata values (@SelectIndex,@SiteName,@ShuiWei,@LiuLiang,@LiuLiang_Total,@YuLiang,@MYL,@YYL,@date_time)
 set @SelectIndex=@SelectIndex+1
 end
 select * from #tempLastdata

------解决方案--------------------

Assembly code

--试下这个速度是多少
alter proc [dbo].[SelectLastData]
as
declare 
@Month varchar(50),
@Year varchar(50)

Select @Month=MAX(CONVERT(varchar(7),date_time,120)),@Year=MAX(CONVERT(varchar(4),date_time,120)) from HistoryData;

if object_id('tempdb..#tempLastdata') is not null drop table #tempLastdata;
select SiteID,SiteName=convert(varchar(50),''),
    ShuiWei,LiuLiang,LiuLiang_Total,YuLiang,
    MYL=convert(varchar(50),''),
    YYL=convert(varchar(50),''),
    Date_Time
into #tempLastdata 
from LastData where 1=2;
insert into #tempLastdata
    select SiteID,ShuiWei,LiuLiang,LiuLiang_Total,YuLiang,Date_Time
    from LastData;
if object_id('tempdb..#t1') is not null drop table #t1;
select SiteID,sum(case when convert(varchar(7),date_time,120)>@Month then Yuliang
    else 0 end) myl,
    sum(Yuliang) yyl
into #t1
from HistoryData 
where convert(varchar(4),date_time,120) >= @Year
group by SiteID;
update #tempLastdata
    set MYL=#t1.myl,
        YYL=#t1.yyl
    from #t1
    where #t1.SiteID=#tempLastdata.SiteID;
update #tempLastdata
    set SiteName=SiteInfo.SiteName
    from SiteInfo 
    where #tempLastdata.SiteID=SiteInfo.SiteID;
select * from #tempLastdata order by SiteID;
drop table #tempLastdata,#t1;
go

------解决方案--------------------

SQL code

ALTER proc [dbo].[SelectLastData]
as
create table #tempLastdata
(
    SiteID int,
    SiteName varchar(50),
    ShuiWei varchar(50),
    LiuLiang varchar(50),
    LiuLiang_Total varchar(50),
    YuLiang varchar(50),
    MYL varchar(50),
    YYL varchar(50),
    date_time datetime 
)
  
declare @SiteID varchar(50),
    @SiteName varchar(50),
    @ShuiWei varchar(50),
    @LiuLiang varchar(50),