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