sql语句怎么写?

declare @Date1 datetime,@Date2 datetime, @Day varchar(2)

set @Date1='20080301'

set @Date2=dateadd(month,1,@Date1)



declare @SQL varchar(8000)

set @SQL='select 物料=b.wlid,供应商=a.gysid'

set @SQL=@SQL+',上旬=sum(case (day(b.日期)-1)/10 when 0 then b.dhsl else 0 end)'

set @SQL=@SQL+',中旬=sum(case (day(b.日期)-1)/10 when 1 then b.dhsl else 0 end)'

set @SQL=@SQL+',下旬=sum(case when (day(b.日期)-1)/10>1 then b.dhsl else 0 end)'

set @SQL=@SQL+',总数=sum(b.dhsl)'

set @Day=1

while @Day<=day(@Date2-1)

begin

	set @SQL=@SQL+',['+@Day+']=sum(case day(b.日期) when '+@Day+' then b.dhsl else 0 end)'

	set @Day=@Day+1

end



set @SQL=@SQL+' from cggl_cgdd as a join cggl_cgddmxb as b on a.fid=b.cgddid'

set @SQL=@SQL+' where b.日期>='''+convert(varchar,@Date1,121)+''''

set @SQL=@SQL+' and b.日期<'''+convert(varchar,@Date2,121)+''' group by b.wlid,a.gysid'

/*

表1   cggl_cgdd  

fid int primary key, 

rq datetime(8), 

gysid ,int               ---供应商编码 

..... 

表2   cggl_cgddmxb 

fid   int primary , 

cgddid  int ,---fk       ---外码  与cggl_cgdd fid 关联 

wlid int,                ----物料编码 

dhsl numeric , 

rq   datetime



要求一个月内的物料供应信息 

物料 供应商 上旬 中旬 下旬  总数  1 2 3 .....31 

*/



select 物料,

       供应商,

       datepart(m,rq) [month],

       上旬= sum(case when day(rq) between 1 and 10 then dhsl else 0 end),

       中旬= sum(case when day(rq) between 10 and 20 then dhsl else 0 end),

       上旬= sum(case when day(rq)>20 then dhsl else 0 end), 

       总数 = sum(dhsl),

       [1]=sum(case when day(rq)= 1 then dhsl else 0 end),

       [2]=sum(case when day(rq)= 2 then dhsl else 0 end),

        ..................

from ta1 a,ta2 b

where a.gysid = b.gysid

group by 物料,

         供应商,

         datepart(m,rq)