처음에 mysql 설치하고나서 외부에서 접속하기 위한 커맨드
mysql> grant all privileges on *.* to root@"%" identified by '암호돠아아아아아' with grant option;
mysql> select host, user from user;
+-----------+------+
| host | user |
+-----------+------+
| % | root |
| localhost | root |
+-----------+------+
