buki\Pdox::avg PHP Метод

    public function avg($field, $name = null)
    {
        $func = "AVG(" . $field . ")" . (!is_null($name) ? " AS " . $name : "");
        $this->select = $this->select == '*' ? $func : $this->select . ", " . $func;
        return $this;
    }