通過 order_id 獲取 參與拼團的 人 的頭像

 /**
  * 通過 order_id 獲取 參與拼團的 人 的頭像.
 */
    public function get_order_pintuan_head_pic($order_id)
    {
        $pt_id = null;
        $pintuan_list = M('order_pintuan')->where(array('order_id' => $order_id))->select();
        if (count($pintuan_list) > 0) {
            foreach ($pintuan_list as $key => $val) {
                if (null == $pt_id) {
                    $pt_id = $val['sub_order_id'];
                } else {
                    $pt_id = $pt_id.','.$val['sub_order_id'];
                }
            }
        }

        $pintuan_list = M('order_pintuan')->where(array('sub_order_id' => $order_id))->select();
        if (count($pintuan_list) > 0) {
            foreach ($pintuan_list as $key => $val) {
                if (null == $pt_id) {
                    $pt_id = $val['order_id'];
                } else {
                    $pt_id = $pt_id.','.$val['order_id'];
                }
            }
        }

        //找出user_id
        $con['order_id'] = array('in', $pt_id);
        $pintuan_list_user_id = M('order')->where($con)->field('user_id')->select();
        $pt_user_id = null;
        foreach ($pintuan_list_user_id as $key => $val) {
            if (null == $pt_user_id) {
                $pt_user_id = $val['user_id'];
            } else {
                $pt_user_id = $pt_user_id.','.$val['user_id'];
            }
        }

        $con['user_id'] = array('in', $pt_user_id);
        $pintuan_list_head_pic = M('users')->where($con)->field('user_id,head_pic')->select();

        return $pintuan_list_head_pic;
    }