use mysql; 
grant all on *.* to root@'%' identified by '123' with grant option; 
commit;

grant all on *.* to xing@'localhost' identified by '123456' with grant option; 
update user set password = password('newpwd') where user = 'xing' and host='localhost'; 
flush privileges;

create database testdb;

create database if not testdb;

use testdb; 
create table table1( 
username varchar(12), 
password varchar(20));

create table if not exists aaa(ss varchar(20));

describe table1;

insert into table1(username,password) values 
('leizhimin','lavasoft'), 
('hellokitty','hahhahah'); 
commit;

select * from table1;

update table1 set password='hehe' where username='hellokitty'; 
commit;

delete from table1 where username='hellokitty'; 
commit;

alter table table1 add column( 
 sex varchar(2) comment '性别', 
 age date not null comment '年龄' 
); 
commit;

create table tmp as 
select * from table1;

drop table if exists table1; 
drop table if exists tmp;

mysqldump -h 192.168.3.143 -u root -p pwd -x --default-character-set=gbk >C:\testdb.sql

drop database testdb;

mysql -u root -pleizhimin testdb <C:\testdb.sql