Prepared Statements
$handle = new PDO('mysql:host=localhost;dbname=ajax');
$statement = $handle->prepare('SELECT `id`, `name` FROM `users` WHERE `login` = ? AND `password` = ?');
$statement->execute(array($username, $password_hash));
if ($user = $statement->fetch(PDO::FETCH_ASSOC)) {
echo $user['id'],"\t",$user['name'],"\n";
} else {
echo "No user found.\n";
}