WITH t AS
(
SELECT 1 idx, '사과' nm, 20000 amt
UNION ALL SELECT 2, '사과', 43200
UNION ALL SELECT 3, '배'  , 30000
UNION ALL SELECT 4, '배'  , 20000
)
SELECT idx
     , nm
     , amt
     , CASE  ROW_NUMBER() OVER(PARTITION BY nm ORDER BY idx) WHEN 1 THEN nm END nm_1
     , CASE WHEN  LAG(nm) OVER(PARTITION BY nm ORDER BY idx) = nm THEN NULL ELSE nm END nm_2
     , NULLIF(nm, LAG(nm) OVER(PARTITION BY nm ORDER BY idx)) nm_3
  FROM t
;