public function execute($config = null)
    {

        if(null == $config){
            $pdo = Config::getDefault()->getPdo();
        }else if($config instanceof \PDO){
            $pdo = $config;
        }else if($config instanceof Config){
            $pdo = $config->getPdo();
        }else{
            throw new BadParameterException('First parameter of FQuery::execute is not correct');
        }

        $stmt = $this->getPdoStatement($pdo);

        if ($stmt->execute()) {
            return $stmt;

        } else {
            // TODO : handle errors ".__FILE__.":".__LINE__;
            throw new QueryFailedException($stmt);
            //return false;
        }

    }