1.Create User
语法：CREATE USER ‘username‘@‘host‘ IDENTIFIED BY ‘password‘;
eg：
CREATE USER ‘pig‘@‘192.168.1.101‘ IDENDIFIED BY ‘123456‘; // 这里限定了可访问的主机的ip为192.168.1.101
CREATE USER ‘pig‘@‘%‘ IDENTIFIED BY ‘123456‘; //表明任何主机都可以访问
create user jss; //可以从任意安装了mysql客户端，并能够访问目标服务器的机器上创建连接，无须密码
2.Grant语句
语法：grant 权限1,权限2,...权限n on 数据库名称.表名称 to 用户名@用户地址 identified by ‘连接口令‘;
eg：
grant select,insert,update,delete,create,drop on mydb.user to [email protected] identified by ‘123‘;//给来自192.168.1.101的用户admin分配可对数据库mydb的user表进行select,insert,update,delete,create,drop等操作的权限，并设定口令为123。
grant all privileges on mydb.* to [email protected] identified by ‘123‘;//给来自192.168.1.101的用户admin分配可对数据库mydb所有表进行所有操作的权限，并设定口令为123
grant all privileges on *.* to [email protected] identified by ‘123‘;//给来自192.168.1.101‘的用户admin分配可对所有数据库的所有表进行所有操作的权限，并设定口令为123
3.直接向表中插入数据
insert into user (host,user,password) values (‘%‘,‘admin‘,password(‘123‘));
flush privileges; //刷新系统权限表
4.修改密码
4.1.使用mysqladmin
语法：mysqladmin -u用户名 -p旧密码 password 新密码
eg：
mysqladmin -u root -p 123 password 456；
4.2.直接修改user表的用户口令
语法：update mysql.user set password=password(‘新密码‘) where User="phplamp" and Host="localhost";
eg：
update user set password=password(‘54netseek‘) where user=‘root‘;
flush privileges; //刷新一下系统权限表
4.3.使用SET PASSWORD语句修改密码
语法：SET PASSWORD FOR ‘username‘@‘host‘ = PASSWORD(‘newpassword‘);
如果是当前用户则去掉FOR ‘username‘@‘host‘
5.取消账户和其授权
Drop USER user;
drop user [email protected]‘%‘
drop user [email protected]
6.去掉权限
语法：REVOKE privilege ON databasename.tablename FROM ‘username‘@‘host‘;
eg：
REVOKE SELECT ON test.user FROM ‘pig‘@‘%‘;
revoke all on user.* from ‘admin‘@‘%‘;
SHOW GRANTS FOR ‘pig‘@‘%‘; //查看授权
7.删除账户
语法: Delete from user where user = "user_name" and host = "host_name" ;
eg:
delete from user where user=‘admin‘ and host=‘localhost‘;