题解 | #找出每个学校GPA最低的同学#

子查询

select device_id,university,gpa

from user_profile

where (university,gpa) in

(select university,min(gpa) as gpa

from user_profile

group by university)

order by university

内连接 + 子查询

select a.device_id,a.university,a.gpa from user_profile a

join (select university,min(gpa) as gpa

from user_profile

group by university) b

on a.university = b.university and a.gpa = b.gpa

order by university;

窗口函数

select device_id,university,gpa

from

(select device_id,university,gpa,row_number() over(partition by university order by gpa) as number

from user_profile) a

where a.number = 1

order by university