http://www.gurubee.net/article/79060

SELECT *
  FROM (SELECT '참외' c1, '딸기' c2, '바나나' c3, '배' c4, '수박' c5 FROM dual)
 UNPIVOT (c FOR gb IN (c1, c2, c3, c4, c5))
;

SELECT lv
     , DECODE(lv, 1, c1, 2, c2, 3, c3, 4, c4, 5, c5) c
  FROM (SELECT '참외' c1, '딸기' c2, '바나나' c3, '배' c4, '수박' c5 FROM dual)
     , (SELECT LEVEL lv FROM dual CONNECT BY LEVEL <= 5)
;