A.Select* From Student Where Sex=’男’ B.Select* From Student Where Number NotIn(Select Number From Student Where Sex<>=’男’) C.Select* From Student Where NumberIn(Select Numbe rFrom Student Where Sex=’男’) D.Select* From Student Where Sex<>’男’
A.Select Count(1)From Student B.Select Sum(*)From Student C.Selec tAvg(*)From Student D.Select Count(*)From Student
A.左外連接 B.右外連接 C.內(nèi)連接 D.自身連接