#Homebrewのアップデート
$ brew update

#MySQLのインストール
$ brew install mysql

Already downloaded: /Users/username/Library/Caches/Homebrew/downloads/*****--mysql-8.0.19.catalina.bottle.2.tar.gz
==> Pouring mysql-8.0.19.catalina.bottle.2.tar.gz
==> /usr/local/Cellar/mysql/8.0.19/bin/mysqld --initialize-insecure --user=username --basedir=/usr/local/Cellar/mysql/8.0.19 --datadir=/usr/local/var/mysql --tmpdir=/tmp
==> Caveats
We've installed your MySQL database without a root password. To secure it run:
    mysql_secure_installation

MySQL is configured to only allow connections from localhost by default

To connect run:
    mysql -uroot

To have launchd start mysql now and restart at login:
  brew services start mysql
Or, if you don't want/need a background service you can just run:
  mysql.server start
==> Summary
🍺  /usr/local/Cellar/mysql/8.0.19: 286 files, 289.2MB

We've installed your MySQL database without a root password

#バージョン確認
$ mysql --version

mysql  Ver 8.0.19 for osx10.15 on x86_64 (Homebrew)

#MySQLのセキュリティ設定
$ mysql_secure_installation

 Securing the MySQL server deployment.

Enter password for user root: 初期パスワードを入力する

The existing password for the user account root has expired. Please set a new password.

New password: 新しいパスワードを入力する

Re-enter new password: 再度同じ新しいパスワードを入力する

VALIDATE PASSWORD PLUGIN can be used to test passwords
and improve security. It checks the strength of password
and allows the users to set only those passwords which are
secure enough. Would you like to setup VALIDATE PASSWORD plugin?

Press y|Y for Yes, any other key for No: y

There are three levels of password validation policy:

LOW Length >= 8
MEDIUM Length >= 8, numeric, mixed case, and special characters
STRONG Length >= 8, numeric, mixed case, special characters and dictionary file

Please enter 0 = LOW, 1 = MEDIUM and 2 = STRONG: 0
Using existing password for root.

Estimated strength of the password: 100
Change the password for root ? ((Press y|Y for Yes, any other key for No) : y

New password: ポリシーに沿った新しいパスワードを入力

Re-enter new password: 再度新しいパスワードを入力する

Estimated strength of the password: 50
Do you wish to continue with the password provided?(Press y|Y for Yes, any other key for No) : y
By default, a MySQL installation has an anonymous user, a user account created for them. This is intended only for
testing, and to make the installation go a bit smoother.
You should remove them before moving into a production
environment.

Remove anonymous users? (Press y|Y for Yes, any other key for No) : y
Success.


Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network.

Disallow root login remotely? (Press y|Y for Yes, any other key for No) : y
Success.

By default, MySQL comes with a database named 'test' that
anyone can access. This is also intended only for testing,
and should be removed before moving into a production
environment.


Remove test database and access to it? (Press y|Y for Yes, any other key for No) : y Success.

- Removing privileges on test database...
Success.

Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.

Reload privilege tables now? (Press y|Y for Yes, any other key for No) : y
Success.

All done!

"MySQLの起動
$ mysql.server start

Starting MySQL
 SUCCESS! 

$ mysql.server start

Starting MySQL
. ERROR! The server quit without updating PID file (/usr/local/var/mysql/マック名local.pid).

# PIDファイルについて確認
$ ls -la /usr/local/var/mysql/XXXXXXXX.local.pid
# PIDがファイルが存在しないとのこと
ls: /usr/local/var/mysql/XXXXXXXX.local.pid: No such file or directory

#PIDファイルの作成
$ touch /usr/local/var/mysql/****.local.pid

$ sudo chown -R _mysql:_mysql /usr/local/var/mysql

#手動での削除
$ $ sudo rm -rf /usr/local/var/mysql
#MySQLのアンインストール
$ brew uninstall mysql
#MySQLの再インストール
$ brew install mysql