//更新数据
    public function update(){
        $wx = M('wxmenu');
        $map['pid'] = 0;
        //查询主菜单数据
        $wxmenu = $wx->where($map)->select();
        $arr = array();
        //循环主菜单
        foreach ($wxmenu as $key => $value) {
            $parent_arr = array();
            $map['pid'] = $value['id'];
            $submenu = $wx->where($map)->select();
            //判断是否有子菜单(默认有)
            $has_sub = true;
            //如果没有子菜单
            if(empty($submenu)){
                $parent_arr['type'] = $value['type'];
                $has_sub = false;
            }
            $parent_arr['name'] = $value['name'];
            //控制显示顺序
            if(!$has_sub){
                $parent_arr[$value['type'] == 'click' ? 'key' : 'url'] = $value['url'];
            }
            $subdata = array();
            //循环子菜单
            foreach ($submenu as $k=>$v) {
                $tmp_ku = $v['type'] == 'click' ? 'key' : 'url';
                $tmp_arr = array(
                    'type'  => $v['type'],
                    'name'  => $v['name'],
                    $tmp_ku => $v['url']
                );
                array_push($subdata,$tmp_arr);
            }
            if($has_sub){
                $parent_arr['sub_button'] = $subdata;
            }
            array_push($arr,$parent_arr);
        }
        dump($arr);
        dump($arr[0]);
        //转化成json结构
        echo json_encode(array('button'=>$arr));
        die();
    }