题解 | 找出每个学校GPA最低的同学

SELECT device_id, university, gpa
FROM (
    SELECT 
        device_id, 
        university, 
        gpa,
        ROW_NUMBER() OVER (
            PARTITION BY university 
            ORDER BY gpa ASC
        ) AS rn
    FROM user_profile
) t
WHERE rn = 1
ORDER BY university;