mysql 创建表并设置主键自增

mysql 创建表： mysql> create table user(    -> userid int(4) primary key not null auto_increment,    -> username varchar(16) not null,    -> userpassword varchar(32) not null    -> );   create table log(logid int(4) primary key not null auto_increment,logtitle varchar(32) not null,logcontent varchar(160) not null,logtime datetime not null,userip varchar(64) not null);