I\'m running OS X 10.11 El Capitan with its built-in server stack (Apache 2.4.16, MySQL 5.6.26).
I need to quit mysql, but killing the process immediately restarts i
As per Theory's answer, this is still effective for Mojave.
sudo launchctl unload -F /Library/LaunchDaemons/com.oracle.oss.mysql.mysqld.plist
Per amacrobert, if you are facing this issue of mysqld continuing starting up, this is most likely due to you having mysql installed on the system level and by default, it will startup automatically on a computer restart.
In my situation, I was confused after a computer restart why my docker mysql container complained about an already allocated port. After continual debugging, I remember I installed mysql on the system level and never restarted my computer!
Cheer.