private function _nullNotPresentIds($klass, $foreign, $ids, $id)
    {
        $escape  = Driver::$escape_char;
        $klasspk = $klass::getPK();
        $klass   = strtolower($klass);
        $table   = Model::getTableName($klass);
        $sql     = "update $escape$table$escape set $escape$foreign$escape=null where $escape$foreign$escape=$id and $escape$table$escape.$escape$klasspk$escape not in ($ids)";
        $stmt    = self::query($sql);
        self::closeCursor($stmt);
    }