每天的最大值--convert(varhcar(10),RsTime,120)--显示天作为组
group   by   StationID ,convert(varhcar(10),RsTime,120)

CREATE   PROCEDURE   GetMaxEx 
@Beginning_Date   datetime, 
@EndDate   datetime   
AS 
begin 

select   
d.StationName,d.xian,d.height,d.Longitude,d.Latitude,   
c.*  
 from 
( 
select 
      StationID,
        convert(varhcar(10),RsTime,120) as 天 
        max_val=max(Temperature), 
        time_at_max=min(RsTime) 
from   
(select  
     StationID,
    RsTime,Temperature   
from   zdzRecord     
where   
    RsTime> =   @Beginning_Date     and   RsTime <@EndDate   and   Temperature> -9999)     a 

where   
    a.Temperature=(select   max(Temperature)  
         from   zdzRecord   where  DATEDIFF(RsTime,aRsTime)=0        --条件
     RsTime> =@Beginning_Date     and   RsTime <@EndDate   and   StationID=a.StationID     ) 

group   by   StationID  ,convert(varhcar(10),RsTime,120) --加上
)   c, 
StationInfo   d   
where   c.StationID   =   d.StationID  order   by   d.xian 

end 
GO

------解决方案--------------------
SQL code
SELECT a.* FROM tb a
INNER JOIN
    (SELECT CONVERT(VARCHAR(10),RsTime,120) dd,MAX(Temperature) mp
        FROM tb
            WHERE RsTime >= @Beginning_Date AND RsTime <@EndDate AND Temperature> -9999
            GROUP BY CONVERT(VARCHAR(10),RsTime,120)
    )b
    ON CONVERT(VARCHAR(10),RsTime,120)=dd AND Temperature=mp