题解 | #找出每个学校GPA最低的同学#

select q.device_id,q.university,q.gpa 
from 
(select
device_id,
university,
gpa ,
rank() over(partition by university order by gpa) as rk
from user_profile
group by device_id,university,gpa
order by university asc) q
where
rk=1;