当月第几个星期：

方法一： datepart(week,OrderDate)-datepart(week,OrderDate-day(OrderDate))+1
方法二： datediff(week,DATEADD(mm,   DATEDIFF(mm,0, OrderDate),   0), OrderDate)+1 

 

--行列转换，显示的列，必需出现在聚合函数，或 group by   

select uvw.upclassname ,
sum(case when (datepart(wk,uvw.orderdate)=datepart(wk,'2009-6-1'))  then (uvw.orderqty) else 0 end  ) 'first week' ,
sum(case when  (datepart(wk,orderdate)-1=datepart(wk,'2009-6-1'))  then orderqty else 0 end  ) 'second week',
sum(case when  (datepart(wk,orderdate)-2=datepart(wk,'2009-6-1'))  then orderqty else 0 end  ) 'third week',
sum(case when  (datepart(wk,orderdate)-3=datepart(wk,'2009-6-1'))  then orderqty else 0 end  ) 'fourth week',
sum(case when  (datepart(wk,orderdate)-4=datepart(wk,'2009-6-1'))  then orderqty else 0 end  ) 'fifth week'
from ( select upclassname,sum(orderqty) orderqty,orderdate from uvw_orderlistforqty
group by upclassname,orderdate having sum(orderqty) >0 ) as uvw

 
查看#建立的临时表

select   *   from   sysobjects   where   name   like   '#t%'  
Drop   Table   #t