Question

几道SQL问题！！急求答案！！

s(sno,class,sname,sex)
c(cno,cname,tname)
sc(sno,cno,score)
1、同时选修了课程编号为c001及c002的学生学号和姓名
2、全部学生都选修的课程编号和课程名
3、选修了张三老师所授所有课程的学生学号

Answer 1

1.
select sno,sname from s where sno in (
select sno from sc where sc.cno='c002' and sc.sno in (select sc.sno from sc where sc.cno='c003')
);

2. 3.. 等楼下回答