This question is a bit outdated but I thought I'd post how I resolved this issue when it happened đồ sộ mạ on my Mac (OS X El Capitan 10.11.4).
Check the status just đồ sộ be sure
mysql.server status
ERROR! MySQL is running but PID tệp tin could not be found
Find all running mysql processes
ps aux | grep mysql
It will list out all the processes using mysql (including the command you just executed)
Kill off all the mysql pids
sudo kill ...
This should kill off all the mysql processes
Now try đồ sộ fire mysql up
mysql.server start
Starting MySQL . SUCCESS!
Hope this helps someone!
EDIT: Alternative solution from @DanielTate
This worked for mạ JasperSoft Wiki - uninstall-mysql-mac-os-x. I had đồ sộ brew uninstall mysql then delete ALL of the files then reinstall and follow the trang chủ brew install instructions
EDIT 2: Alternative solution from @JanacMeena
There is a nice write-up of their solution in this post on Medium.