（1）查询“金羽”同学所选课程的成绩。
select cno,degree from sc
where sno in (select sno from student where sname=' 金羽 ');
（2）查询“李新”老师所授课程的课程名称。
select cname from course
where cno=(select cno from teaching where tno=(select Tno from teacher where Tname=' 李新 '));
（3）查询女教师所授课程的课程号及课程名称。
select cno,cname from course
where cno in (select cno from teaching where tno in(select Tno from teacher where Tsex=' 女 '));
（4）查询姓“王”的学生所学的课程名称。
select cname from course
where cno in (select cno from sc where sno in (select sno from student where sname like ' 王 %') );
（5）查询“C04”课程不及格的学生信息。
select * from student
where sno in (select sno from sc where cno='c04' and degree<60);
（6）查询选修“高等数学”课程且成绩在80～90分的学生学号及成绩。
select sno,degree from sc
where cno = (select cno from course where cname=' 高等数学 ') and degree between 80 and 90;
（7）查询选修“C04”课程的学生的平均年龄。
select avg(year(curdate())-year(sbirthday)) from student
where sno in (select sno from sc where cno='c04');
（8）查询选修课程名为“高等数学”的学生学号和姓名。
select sno,sname from student
where sno in (select sno from sc where cno=(select cno from course where cname=' 高等数学 '));
（9）查询“钱军”教师任课的课程号，选修其课程的学生的学号和成绩。
select c.cno,sno,degree from teaching b,sc c
where b.cno=c.cno and Tno=(select Tno from teacher where Tname=' 钱军 ');
或者：
SELECT sno,cno,degree FROM sc WHERE cno in
(SELECT cno FROM teaching WHERE tno=(SELECT tno FROM teacher WHERE tname=' 钱军 '))
select cname,degree from course a,sc b
where a.cno=b.cno and b.cno in (select cno from teaching where cterm=1);
select sname from student
where classno in (select classno from student where sname=' 金羽 ');
（12）查询学号比“金羽”同学大，而出生日期比他小的学生姓名。
select sname from student
where sno> (select sno from student where sname=' 金羽 ')
and year(curdate())-year(sbirthday)< (select year(curdate())-year(sbirthday) from student where sname=' 金羽 ');
（13）查询出生日期大于所有女同学出生日期的男同学的姓名及班级编号。
select sname,classno from student
where sbirthday>all (select sbirthday from student where ssex=' 女 ')
and ssex=' 男 ';
（14）查询不讲授“C01”课的教师姓名。
select Tname from teacher
where Tno not in (select tno from teaching where cno='c01' );
（15）查询没有选修“C02”课程的学生学号及姓名。
select sno,sname from student
where sno not in (select sno from sc where cno='c02');
（16）查询选修了“JAVA程序设计基础”课程的学生学号、姓名及班级编号。
select sno,sname,classno from student
where sno in (select sno from sc
where cno=(select cno from course where cname=' JAVA程序设计基础 '));
