WITH t AS
(
SELECT 1 id, 'A' nm, '중간' st1, '완료' st2
UNION ALL SELECT 2, 'A', '결과', '완료'
UNION ALL SELECT 3, 'B', '중간', '완료'
UNION ALL SELECT 4, 'B', '결과', '진행'
UNION ALL SELECT 5, 'C', '중간', '진행'
UNION ALL SELECT 6, 'C', '결과', '진행'
)
SELECT *
  FROM (SELECT id, nm, st1, st2
             , ROW_NUMBER() OVER(PARTITION BY nm
               ORDER BY st2
                      , CASE st2 WHEN '완료' THEN st1 END
                      , CASE st2 WHEN '진행' THEN st1 END DESC
                      ) rn
          FROM t
        ) a
 WHERE rn = 1
;