Swoole\Model::getMap PHP Method

    function getMap($gets, $field = null)
    {
        $list = $this->gets($gets);
        $new = array();
        foreach ($list as $li) {
            if (empty($field)) {
                $new[$li[$this->primary]] = $li;
            } else {
                $new[$li[$this->primary]] = $li[$field];
            }
        }
        return $new;
    }