Login php

function user_login() {
    $login_user = "alex";
    $login_pass = "parola";

    $query = "SELECT * FROM `users` WHERE (`username`='".$login_user."' OR `email`='".$login_user."') AND `password`='".$login_pass."' LIMIT 1";
    $result = $db_link->query($query);

    while ($row=$result->fetch_assoc())
    {
        if (!empty($row))
        {
            //Totul bine
            return true;
        }
    }
    return false;
}