• 2022-06-19
    下列函数依赖中属于平凡函数依赖的有()
    A: (Sno,Cname)->(Cname,Grade)
    B: (Sno,Cname)->(Sname,Grade)
    C: (Sno,Sname)->Sname
    D: (Sno,Cname,Grade)->(Cname,Grade)
  • 举一反三