ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock'

This seems to happen every time you restart your machine occurs. The solution is to start your SQL server as it has been turned off when the machine restarted:
sudo mysql.server start

Source: https://stackoverflow.com/questions/15450091/error-2002-hy000-cant-connect-to-local-mysql-server-through-socket-tmp-mys