Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock'

Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock'

Solution:
sudo service mysql stop
sudo /etc/init.d/apparmor reload
sudo service mysql start 

PHP Get Id youtube from URL link

<?php
if (strpos($video, 'youtube') > 0) {
    preg_match("#(?<=v=)[a-zA-Z0-9-]+(?=&)|(?<=v\/)[^&\n]+(?=\?)|(?<=v=)[^&\n]+|(?<=youtu.be/)[^&\n]+#", $video, $matches);
    $_video = 'https://www.youtube.com/embed/' . $matches[0];
}