with tmp as (
    select '1' ord_no, 'a1' col1, '031-01' col2, '박이름' b, '냉장고' c from dual
    union all select '2' ord_no, 'a4' col1, '02-02' col2, '이순신' b, '밥상' c from dual
    union all select '3' ord_no, 'a3' col1, '031-04' col2, '정인숙' b, '노트북' c from dual
    union all select '4' ord_no, 'a1' col1, '02-02' col2, '박순자' b, '티비' c from dual
    union all select '5' ord_no, 'a6' col1, '031-01' col2, '이말자' b, '거울' c from dual
)
select
    ord_no, max(col1), max(col2), max(b), max(c)
from (
    select
        t.ord_no, col1 || '(중)' col1,  col2 ,   t.b, t.c
    from tmp t
    where exists ( select 'x' from tmp a where a.ord_no <> t.ord_no and a.col1 = t.col1)
    union all
    select
        t.ord_no, col1 ,  col2 || '(중)',   t.b, t.c
    from tmp t
    where exists ( select 'x' from tmp a where a.ord_no <> t.ord_no and a.col2 = t.col2)
)
group by ord_no
order by ord_no
 

WITH t AS
(
SELECT 1 no, 'a1' ord_no, '031-01' tel_no, '박이름' name, '냉장고' item FROM dual
UNION ALL SELECT 2, 'a4', '02-02' , '이순신', '밥상'   FROM dual
UNION ALL SELECT 3, 'a3', '031-04', '정인숙', '노트북' FROM dual
UNION ALL SELECT 4, 'a1', '02-02' , '박순자', '티비'   FROM dual
UNION ALL SELECT 5, 'a6', '031-01', '이말자', '거울'   FROM dual
)
SELECT no
     , ord_no || CASE WHEN ord_cnt > 1 THEN '(중)' END ord_no
     , tel_no || CASE WHEN tel_cnt > 1 THEN '(중)' END tel_no
     , name
     , item
  FROM (SELECT no
             , ord_no
             , tel_no
             , name
             , item
             , COUNT(*) OVER(PARTITION BY ord_no) ord_cnt
             , COUNT(*) OVER(PARTITION BY tel_no) tel_cnt
          FROM t
        )
 WHERE 1 < ANY(tel_cnt, ord_cnt)
 ORDER BY no
;

두분 답글 정말 감사드려요  ^^

저도 감사합니다. pk가 중복나는 문제로 걸러내야 했는데...님의 글로 해결되었습니다. 꾸벅