创建用户: create user 'alex'@'192.168.1.1' identified by '123123';  用户名为alex, 密码是'123123', 服务器的ip ‘192.168.1.1’

              create user 'alex'@'192.168.1.%' identified by '123123'; 用户名为alex, 密码是'123123', 服务器的ip为'192.168.1.%'

              create user 'alex'@'%'identified by '123123' ; 用户名为alex, 密码是'123123',服务器的ip为'%' 

用户ip登录:  mysql -h localhost -u root -p 

删除用户: drop user 'alex'@'192.168.1.1'

修改用户: rename user 'alex'@'192.168.1.1' to 'alex'@'192.168.1.2'

修改密码: set password for 'alex'@'192.168.1.2' = '123456' 

查看当前用户: select host,userfrom user;

授权: grant select, insert, update on db1.* to 'alex'@'%' 对alex用户进行db1数据库的所有表的查询,插入，修改操作 

        grant all privileges on db1.t1 to 'alex'@'%'; 对alex用户进行db1数据库的表t1的所有操作授权 

        remove all privileges on db1.t1 from 'alex'@'192.168.1.1'; 将alex用户对于db1中表t1的权限删除