求一个简单sql查询语句?
现有3个表如下：
S(Sno, Sname, Ssex, Sage, Sdep)
学号，名字，性别，年龄，所在院系
C(Cno, Cname, Ccredit, Cpno)
课程号，课程名，学分，先修课程号
SC(Sno, Cno, Grade)
学号，课程号，成绩
所求问题：
查询平均成绩最高的学生学号，姓名和平均成绩？
小弟刚刚入门，道行不够，还请各位指点一下！
没多少分，先谢谢了！
[解决办法]
select s.sno as sno,s.sname as sname avg(sc.grade) as avggrade from s,c,sc where s.sno=sc.sno and c.cno=sc.cno and s.sno=sc.sno group by s.sno order by avggrade
大概就是这样
[解决办法]
select s.sno as sno,
s.sname as sname
avg(sc.grade) as avggrade
from s,c,sc
where s.sno=sc.sno and
c.cno=sc.cno and
s.sno=sc.sno and
avg(sc.grade) in (
select max(avg(sc.grade)) from sc group by sc.sno)
