在模型[App \ Models \ Municipal_district]上调用未定义的关系[cities]

Question

City.php

public function municipal_districts()
{
    return $this->hasMany('App\Models\Municipal_district');
}

Municipal_district.php

public function province()
{
    return $this->belongsTo('App\Models\City', 'city_id');
}

哪里可能出错？

Answer 1

城市模型

public function municipal_districts()
{
    return $this->hasMany('App\Models\Municipal_district');
}

Municipal_district模型

public function city()
{
    return $this->belongsTo('App\Models\City', 'city_id');
}

我不知道这里的城市（）关系！

城市有很多ditricts，区域属于一个城市。那么，这里的城市（）是什么？