Getting a database backup via php

<?php
//
// Download a gzipped mysql dump from a remote host
//
// Invoke it via curl with:
//  curl http://remote.site/path/to/script.php -o /path/to/dump.sql.gz
//

// replace with your own values
$username = escapeshellarg("YOUR DATABASE USER");
$password = escapeshellarg("YOUR DATABASE PASSWORD");
$database = escapeshellarg("YOUR DATABASE NAME");

// dump it!
passthru("mysqldump -u$username -p$password $database | gzip");