case whenoracle SQL 查询 case when问题

oracle SQL 查询 case when问题

select a,Case WHEN a>=85 THEN '优秀' WHEN a>=75 THEN '良好'WHEN a>=60 THEN '及格'ELSE '不及格'END,Case WHEN b>=85 THEN '优秀' WHEN b>=75 THEN '良好'WHEN b>=60 THEN '及格'ELSE '不及格'END b from table_