oracle行转列,列转行

第一种：

select custid,
sum(case when YEAR(orderdate)=2002 then qty end) as [2002],
sum(case when YEAR(orderdate)=2003 then qty end) as [2003],
sum(case when YEAR(orderdate)=2004 then qty end) as [2004]
from orders
group by custid;

第二种：
select *
from (select custid,YEAR(orderdate) as years,qty from orders) as ord
pivot(sum(qty) for years in([2002],[2003],[2004]))as p