fastadmin使用数据库数据地区多级联动

/app/controller/Area.php

<?php
namespace app\api\controller;
use app\common\controller\Api;
use think\Db;

/**
 * Area
 */
class Area extends Api
{

    // 无需登录的接口,*表示全部
    protected $noNeedLogin = '*';
    // 无需鉴权的接口,*表示全部
    protected $noNeedRight = [];
     /**
     * 读取省市区数据,联动列表
     */
    public function area()
    {
        $params = $this->request->get("row/a");
        if (!empty($params)) {
            $province = isset($params['province']) ? $params['province'] : null;
            $city = isset($params['city']) ? $params['city'] : null;
        } else {
            $province = $this->request->get('province');
            $city = $this->request->get('city');
        }
        $where = ['pid' => 0, 'level' => 1];
        $provincelist = null;
        if ($province !== null) {
            $where['pid'] = $province;
            $where['level'] = 2;
            if ($city !== null) {
                $where['pid'] = $city;
                $where['level'] = 3;
            }
        }
        $provincelist = Db::name('area')->where($where)->field('id as value,name')->select();
        $this->success('获取成功',$provincelist);
    }

}

html

<script type="text/javascript" src="/assets/libs/jquery/dist/jquery.min.js"></script>
<script type="text/javascript" src="/assets/libs/fastadmin-cxselect/js/jquery.cxselect.js"></script>

{assign name="area" value=":db('area')->where('name','in',explode('/',$user.city))->column('id','name')" /}
{assign name="city" value=":explode('/',$user.city)" /}
<span  data-toggle="cxselect" data-selects="province,city,area">
      <select  name="province" class="province" data-url="/api/area/area.html">
        {if(!empty($city[0]))}<option value="{$area[$city[0]]}" selected="">{$city[0]}</option>{/if}
      </select>
      <select name="city" class="city" data-url="/api/area/area.html">
          {if(!empty($city[1]))}<option value="{$area[$city[1]]}" selected="">{$city[1]}</option>{/if}
      </select>
      <select name="area" class="area"  data-url="/api/area/area.html">
          {if(!empty($city[2]))}<option value="{$area[$city[2]]}" selected="">{$city[2]}</option>{/if}
      </select>
</span>

if ($("[data-toggle='cxselect']").length > 0) {
    $.cxSelect.defaults.jsonName = 'name';
    $.cxSelect.defaults.jsonValue = 'value';
    $.cxSelect.defaults.jsonSpace = 'data';
    $("[data-toggle='cxselect']").cxSelect();
}

php

        $province = $this->request->post('province');
        $city = $this->request->post('city');
        $area = $this->request->post('area');
        
        
        $province = db("area")->where("id",$province)->value('name');
        $city = db("area")->where("id",$city)->value('name');
        $area = db("area")->where("id",$area)->value('name');

        $riku="{$province}/{$city}/{$area}";