Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in

Hello,

I’m a total newbie and need your guys help here. My website just got this message on the top of everypage. How to fix this ? The error that in the line is “$this->dbh = mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, $new_link, $client_flags )”

I found the exact problem in youtube that can be removed by accessing config.php which i can’t find anywhere.

Here’s the youtube link that i found : link

How do i fix this issue. Please help