private function modify()
    {
        if ($this->isIndex()) {
            $this->query = $this->modifyIndex($this->query);
        }
        else if ($this->isShow()) {
            $this->query = $this->modifyShow($this->query);
        }
        else if ($this->isDelete()) {
            $this->query = $this->modifyDelete($this->query);
        }
        else if ($this->isUpdate()) {
            $this->query = $this->modifyUpdate($this->query);
        }

        return $this;
    }