PDO no such file or directory - only ftp server access - php

Question

I'm moving our php administration to a new server (hosted) but while trying out the migrated system, I detected that our code is unable to access the MySql database. The code was working before and the new webhost says it is supporting PDO. We have no ability to access the actual server more than via ftp and phpmyadmin, preventing us from accessing php.ini. We would prefer to be able to keep using PDO.
Any ideas how to fix this, and if not
How could we have this file working in the same/a similar way but without PDO?
Class Database{
protected $_link;
public function __construct(){
$config['db'] = array(
'hostname' => 'localhost', //The provided XXX.loopia.se and 127.0.0.1 has also been attemped here with no result
'dbname' => 'database_name',
'username' => 'user_name',
'password' => 'password'
);
$db = new PDO('mysql:hostname=' . $config['db']['hostname'] .';dbname=' . $config['db']['dbname'], $config['db']['username'], $config['db']['password']);
$this->_link = $db;
}
}
Log output:
PHP Warning: PDO::__construct() [pdo.--construct]: [2002] No such file or
directory (trying to connect via unix:///tmp/mysql.sock)
Link to loopia's "PHP to SQL"-use-this-code: https://support.loopia.se/files/php_till_mysql.zip

Answer 1

After quick feedback from the webhost, the above does not seem to be the preffered way to accomplish this at loopia. For further reference for other googlers, this is the code received (and edited to match the above purpose):
<?php
Class Database{
protected $_link;
public function __construct(){
$hostname = "xXXX.loopia.se"; //Log on to phpmyadmin and see what it says in the top after "server"
$username = "username";
$password = "password";
try {
$db = new PDO("mysql:host=$hostname;dbname=<DBNAME>",
$username,
$password,
array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"));
$this->_link = $db;
}
catch(PDOException $e)
{
echo $e->getMessage();
}
}
}
?>