select a.idx, a.myname, b.selA, b.selB
from (
  select '1111' idx, 'won' myname  from dual union
  select '2222' idx, 'two' myname  from dual
) a
join (
  select idx
         ,max(case when sel='a' then code
               else ''
          end) selA
          ,max(case when sel='b' then code
               else ''
          end) selB
  from (       
    select idx, sel, wm_concat(code) code
    from (
      select '1111' idx, 'a' sel, 'a11' code from dual union
      select '1111' idx, 'a' sel, 'a22' code from dual union
      select '1111' idx, 'b' sel, 'a99' code from dual union
      select '2222' idx, 'a' sel, 'a22' code from dual union
      select '2222' idx, 'a' sel, 'a99' code from dual
    ) g
    group by idx, sel
  ) t
  group by idx
) b on (b.idx=a.idx) 

11g 버전 이후면 wm_concat 대신 ListAgg(code, ',') within group(order by code)

이런식으로 써도 됩니다.

 감사 합니다. 잘 되네여 ^^

주말에는 비온다던데 집에서 오라클 관련 PDF하나 구해서 스터디좀 해야 겠네요