题解 | 查询成绩
查询成绩
https://www.nowcoder.com/practice/ef30689ae065434c89c129e9dfe1b4cd
select
count(*)
from
(
select
s.sid
from
Student s
join SC sc on s.sid = sc.sid
join Course c on c.cid = sc.cid
#where cname='语文' or cname='数学' or cname='英语'
group by
sc.sid
having
avg(sc.score) > 60
) s;
个人认为不需要where的条件，注释后确实仍可运行。
