Connect a MySQL database to a website hosted

I am using hostgator to host my site. The code to code the database to the website is the following:

<?php

$pdo = new PDO('mysql:dbname=fashion;host=10.112.12.15', 'username', 'password');

/*the host part contains the IP address directing to my website.*/

$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);

?>

After executing the code, I get the following error:

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[28000][1045] Access denied for user '

I am wondering why the code is not working. But when I am in local and I use locahost for the host, everything works perfectly.

Kindly help me solve this problem