单选题

如用下列SQL语句创建一个student表：CREATE TAB...

Question

如用下列SQL语句创建一个student表：
CREATE TABLE student(STUDENT_NO int NOT NULL,
NAME char(2) NOT NULL,
SEX char(1),
AGE int)
下列那些关于NULL的写法是错误的

A. select * from student where SEX=NULL

B. select * from student where SEX IS NOT NULL

C. SELECT * from student where SEX<>'M'

D. SELECT * from student where SEX='M'