SQL语句，检索至少选修了“S001”所学课程的学生名单

关系 Student,SC,Course,Teacher
Student(Snum,Sname,Ssex,Sage)
SC(Cnum,Cname,Tnum)
Course(Cnum,Cname,Tnum)

select * from Student
where  Snum in
( select distinct Snum from SC xwhere not exists(select * from SC ywhere y.Snum='S001' and not exists(select * from SC zwhere z.Cnum=y.Cnum and z.Snum=x.Snum))
)