WITH T AS (
SELECT 70 jumsu, '국어' AS kwamok, 's01' AS scod FROM SYSIBM.SYSDUMMY1
UNION ALL SELECT 20 jumsu, '영어' AS kwamok, 's01' AS scod FROM SYSIBM.SYSDUMMY1
UNION ALL SELECT 50 jumsu, '국어' AS kwamok, 's01' AS scod FROM SYSIBM.SYSDUMMY1
)
SELECT scod, kwamok, max(jumsu) max
FROM T
GROUP BY scod, kwamok