测试派 Give testers a home.

1、	查询出语文最高分 
select max(score) as '语文最高分' from sc inner join course as c on c.Cno=sc.Cno where c.Cname='语文' 
2、	查询语数外三门成绩的平均分
select c.Cname,avg(sc.score)as '平均分' from course as c inner join sc on c.Cno=sc.Cno group by c.Cno,c.Cname 
3、	查询报名孤独求败老师课程的学生信息 
select * from student as s inner join sc on s.Sno=sc.Sno inner join course as c on sc.Cno=c.Cno right join teacher as t on t.Tno=c.Tno where t.Tname='孤独求败'

1、 查询出语文最高分
select max(score) as '语文最高分' from sc inner join course as c on c.Cno=sc.Cno
where c.Cname='语文'
2、查询语数外三门成绩的平均分
select c.Cname,avg(sc.score)as '平均分' from course as c inner join sc on c.Cno=sc.Cno
group by c.Cno,c.Cname
3、查询报名孤独求败老师课程的学生信息
select * from student as s inner join sc on s.Sno=sc.Sno
inner join course as c on sc.Cno=c.Cno
right join teacher as t on t.Tno=c.Tno
where t.Tname='孤独求败'