求一SQL语句

Question

select a.id,a.name,
       decode(b.course,1,b.,0) course1,
       decode(b.course,2,b.,0) course2,
       decode(b.course,3,b.,0) course3,
       decode(b.course,4,b.,0) course4,
       .....       
  from a,b
 where a.id=b.id

Answer 1

借鉴楼上的
select a.id,a.name,
       sum(decode(b.course,1,b.,0) course1),
       sum(decode(b.course,2,b.,0) course2),
       sum(decode(b.course,3,b.,0) course3),
       sum(decode(b.course,4,b.,0) course4),
       .....
  from a,b
 where a.id=b.id
group by a.id,a.name