MySQL can connect with localhost, but 127.0.0.1 can't connect

Mysql sets permissions and passwords in units of とuser name@hostname 」.
https://dev.mysql.com/doc/refman/5.6/ja/account-names.html

Also, localhost and 127.0.0.1 are treated differently in mysql and behave differently.
(In the case of localhost, it is socket communication) https://dev.mysql.com/doc/refman/5.6/ja/can-not-connect-to-server.html

In other words,
If only root@localhost was configured with a password or permissions,
[email protected] is undefined.