A.OR B.Not between C.Not IN D.Like
A.Sum返回表達(dá)式中所有數(shù)的總合,因此只能用于數(shù)字類型的列 B.Avg返回表達(dá)式中所有數(shù)的平均值,可以用于數(shù)字型和日期型的列 C.Max和Min可以用于字符型的列 D.Count可以用于字符型的列
A.Select email from student where email !=null B.Select email from student where email not is null C.Select email from student where email <> null D.Select email from student where email is not null