You restarted your Mac server, and you've noticed that the MySQL service has stopped.
Mac servers do not automatically restart MySQL after being restarted.
You have two options for restarting MySQL.
In the System Preferences, click MySQL.
Don't see an option for MySQL in the System Preferences? Copy the following text into the Command line:
sudo /usr/local/mysql/support-files/mysql.server start
Press Enter. MySQL will start.