public function get_user($username, $password) {
    $p = md5($password);
    $q = "SELECT u.userid, u.userfullname, u.useraddress
    FROM user u
    WHERE u.username = ? AND u.userpassword = ?";

    $r = $this->db->query($q, [$username, $p]);
    $this->db->close();
    return $r->result_object();
}