选择学生的名字，其GPA大于课程和专业的平均GPA

Question

我有桌子“学生”：

HTMLElement

如何选择GPA高于其课程和专业平均GPA的学生姓名？

非常感谢

Answer 1

这样的事情应该有效。在这里，我们计算每门课程和专业的平均值，加入学生并从那里过滤。

Select s.name
from students s
inner join
(Select course, speciality, avg(gpa) as avg_gpa from students
group by course, speciality) a
on a.course = s.course and a.speciality = s.speciality
where s.gpa > a.avg_gpa

Answer 2

SELECT name 
FROM student s
INNER JOIN ( 
    SELECT course , speciality , AVG(gpa) gpa
    FROM student
    GROUP BY course , speciality
) a ON s.course = a.course AND s.speciality = a.speciality
WHERE s.gpa > a.gpa