Question

表格：

divisions
    id      name

districts
    id      division_id         name

subdistricts
    id      district_id         name


class Division extends Model
{
    //
    public function districts()
    {
        return $this->hasMany('App\District', 'division_id');
    }

    public function subdistricts()
    {
        // what will be here
    }

}

是否可以通过division_id获取子区域而不使用subdistricts表上的division_id

Answer 1

了解hasManyThrough()关系。因此，subdisctricts()将如下所示：

public function subdisctricts()
{
    return $this->hasManyThrough('App\SubDistrict', 'App\District');
}

Answer 2

您可以按照建议使用hasManyThrough()，hasManyThrough的语法是：

class Division extends Model
{
    public function posts()
    {
        return $this->hasManyThrough(
            'App\Subdistrict', 'App\District',
            'country_id', 'user_id', 'id'
        );
    }
}

第三个参数是foreign key on the intermediate model的名称，第四个参数是foreign key on the final model的名称，第五个参数是local key - See Docs < / p>

Answer 3

您需要使用hasManyThrough来表示此关系。

public function subdisctricts()
{
    return $this->hasManyThrough('App\Subdistrict', 'App\District');
}

Answer 4

您可以尝试hasManyThrough()：

public function subdistricts()
{
    return $this->hasManyThrough('App\Subdistrict', 'App\District');
}

has-many-through关系为通过中间关系访问远距离关系提供了方便的捷径。

Laravel雄辩的关系第3级

4 个答案: