db環境設定で最も基本的なアクセス権限の付与について　

~ % mysql -u root
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

~ % mysql -u root -p
Enter password: 
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

rootにアクセス権限がないようだ...

https://qiita.com/yummy888/items/25621bc1451f218e010a
この記事を参考にしよう。

 % mysql.server stop 
Shutting down MySQL
.. SUCCESS! 

~ % mysqld_safe --skip-grant-tables
2021-02-26T03:02:12.6NZ mysqld_safe Logging to '/usr/local/var/mysql/MacBook-Pro.local.err'.
2021-02-26T03:02:13.6NZ mysqld_safe A mysqld process already exists

...。mysqld_safe A mysqld process already existsとはなんぞや？

この記事を参考にしよう。
mysqld_safe A mysqld process already existsの対処法【MySQL】
https://yaba-blog.com/mysqld_safe-a-mysqld-process-already-exists-mysql/

mysql.server stop だとMySQLが勝手に再起動するらしい
mysql.server statusで確認。

~ % mysql.server stop 
Shutting down MySQL
.. SUCCESS! 
~ % mysql.server status
 SUCCESS! MySQL running (53818)

たしかに、再起動されている。

~ % brew services stop mysql
Stopping `mysql`... (might take a while)
==> Successfully stopped `mysql` (label: homebrew.mxcl.mysql)

再度こちらの記事に戻るhttps://qiita.com/yummy888/items/25621bc1451f218e010a#%E6%A8%A9%E9%99%90%E7%A2%BA%E8%AA%8D

権限なしでアクセス

 ~ % mysqld_safe --skip-grant-tables
2021-02-26T03:22:53.6NZ mysqld_safe Logging to '/usr/local/var/mysql/MacBook-Pro.local.err'.
2021-02-26T03:22:53.6NZ mysqld_safe Starting mysqld daemon with databases from /usr/local/var/mysql

成功

mysqlへ接続

~ %  mysql -u root
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 8.0.22 Homebrew

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

-以下記事通り

権限確認

Userテーブル削除

rootユーザーを作成し、権限付与

mysqld_sefe プロセス終了
ps
-> 現在実行されているプロセス一覧表示

KILL (PID)
-> プロセス終了

~ % mysql.server start
Starting MySQL
. SUCCESS! 
yuto@MacBook-Pro ~ %  mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.22 Homebrew

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

またrootアカウントで作業するのは抵抗がある場合MySQLユーザーの作成を行います。
セキュリティ設定（rootのパスワード変更等）

~%mysql_secure_installation