FastAdmin ThinkPHP5 cms 插件 多字段排序

ThinkPHP5.1，FastAdmin 多字段排序

if($orderby == 'id' && $orderway =='desc'){
    $orderby = 'id desc, price desc';
}elseif($orderby == 'id' && $orderway =='asc'){
    $orderby = 'id asc, price asc';
}

ThinkPHP5.1 Query.php Order 方法

    /**
     * 指定排序 order('id','desc') 或者 order(['id'=>'desc','create_time'=>'desc'])
     * @access public
     * @param string|array $field 排序字段
     * @param string       $order 排序
     * @return $this
     */
    public function order($field, $order = null)
    {
        if (empty($field)) {
            return $this;
        } elseif ($field instanceof Expression) {
            $this->options['order'][] = $field;
            return $this;
        }

        if (is_string($field)) {
            if (!empty($this->options['via'])) {
                $field = $this->options['via'] . '.' . $field;
            }
            if (strpos($field, ',')) {
                $field = array_map('trim', explode(',', $field));
            } else {
                $field = empty($order) ? $field : [$field => $order];
            }
        } elseif (!empty($this->options['via'])) {
            foreach ($field as $key => $val) {
                if (is_numeric($key)) {
                    $field[$key] = $this->options['via'] . '.' . $val;
                } else {
                    $field[$this->options['via'] . '.' . $key] = $val;
                    unset($field[$key]);
                }
            }
        }
        if (!isset($this->options['order'])) {
            $this->options['order'] = [];
        }
        if (is_array($field)) {
            $this->options['order'] = array_merge($this->options['order'], $field);
        } else {
            $this->options['order'][] = $field;
        }

        return $this;
    }