Thinkphp5.1模型远程一对多关联

city表

man表

topic表

代码如下

<?php
namespace app\my\model;
use think\Model;
class City extends Model 
{
    public function topics()
    {
        return $this->hasManyThrough('Topic','Man','city_id','man_id','id');
    }
}

<?php
namespace app\my\model;
use think\Model;
class Man extends Model 
{
}

<?php
namespace app\my\model;
use think\Model;
class Topic extends Model 
{
}

$city = City::get(1);
$city->topics
$city->topics()->where('topic.content','东风公司')->select()