function updateAttd(&$response, array $objs)
{
    /*
    insert into Attendance(lec_id,stud_id,presence) VALUES(1,3,0),(1,6,1),(1,2,1)
    on duplicate key update presence = VALUES(presence)
    */
    try {
        $dbh = new MyDbCon();
        $dbh->multiUpdate($objs, array("presence"));
        $dbh->execute();
        return true;
    } catch (\Exception $e) {
        $message = $e->getPrevious() ? $e->getPrevious()->getMessage() : $e->getMessage();
        $code = $e->getPrevious() ? $e->getPrevious()->getCode() : $e->getCode();
        $err = "Error Code: " . $code . " <br/>Detailed Info: " . $message;
        $response = array('code' => HTTP_Status::FORBIDDEN, 'message' => $err);
        return false;
    }
}