我做留言板数据库是Mesid int(6) null auto_increment
username varchar(20)
password varchar(50)
gender varchar(10)
E-mail varchar(50)
content text
firstMesid int(6)
primary key(Mesid)
sql语句是:insert into guestbook(username,password,gender,E-mail, content,firstMesid)values('$username','$password','$gender','$e-mail','$content',last_insert_id())
结果firstMesid的值一直维持不变