1、创建用户

CREATE USER 'test'@'%'  IDENTIFIED BY '12345678';

2、用户授权

grant all privileges on test.* to "test"@"%" identified by "12345678";

flush privileges; 

3、删除用户

delete from mysql.user where User="test" and Host="%";

flush privileges;

4、删除账户及权限

drop user test@'%';

flush privileges;

5、修改用户密码

update mysql.user set authentication_string=password("新密码") where User="test" and Host="%";

flush privileges;