create database mytest default charset=utf8 //创建数据库

create table users //创建表

(

user_id int not null auto_increment,

user_name varchar(20) not null,

description varchar(200),

primary key PK_userid(user_id)

);

show create table users;//查看创建表的sql语句

desc users; //查看表结构

alter table users add(user_age int not null); //添加表字段

insert into users(user_name,description,user_age) values('chen','this is good men.',28); //插入一条数据

//查询数据库

select * from users limit 5; //查询前5条

SELECT * FROM users LIMIT 6,2; //从弟6条开始，查2条