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 x
  where not exists
  (
    select * from SC y
    where y.Snum='S001' and not exists
   (
     select * from SC z
  where z.Cnum=y.Cnum and z.Snum=x.Snum
   )
  )
)