Laravel 嵌套关系 [英] Laravel nested relationships

问题描述

我无法在 laravel 中建立一个非常嵌套的关系以正常工作.

I'm having trouble getting a very-nested relationship to work correctly in laravel.

想要的行为如下，

我通过 ID 选择一个事件，我想查看哪些人订阅了它.现在的问题是事件和人之间有一些表格..

I select an event by ID and i want to see which persons are subscribed to it. Now the problem is there are some tables between the event and the person..

这是有效的查询！

SELECT persons.id, 
       persons.firstname, 
       persons.lastname, 
       event_scores.score 
FROM   events 
       JOIN cities 
         ON cities.id = events.city_id 
       JOIN companies 
         ON cities.id = companies.city_id 
       JOIN persons 
         ON companies.id = persons.company_id 
       JOIN event_scores 
         ON event_scores.person_id = persons.id 
WHERE  event_scores.event_id = 1 
GROUP  BY persons.id 

这些是我的亲戚

事件模型

class Event extends Eloquent
{
    protected $table = 'events';

    public function city()
    {
        return $this->belongsTo('City');
    }
}

城市模型

class City extends Eloquent
{
    protected $table = 'cities';

    public function companies()
    {
        return $this->hasMany('Company');
    }

    public function event()
    {
        return $this->hasMany('Event');
    }
}

公司模式

class Company extends Eloquent {

    protected $table = 'companies';

    public function persons()
    {
        return $this->hasMany('Person');
    }

    public function city()
    {
        return $this->belongsTo('City');
    }
}

人物模型

class Person extends Eloquent
{
    protected $table = 'persons';

    public function company()
    {
        return $this->belongsTo('Company');
    }

    public function eventscore()
    {
        return $this->belongsToMany('Event', 'event_scores', 'person_id', 'event_id')
            ->withPivot('score')
            ->withTimestamps();
    }
}

我尝试了什么

return Event::with('city')->with('company')->get();

和

return Event::with('city')
    ->whereHas('companies', function($query) use ($company_id){
        $query->where('company_id', $company_id);
    })->get();

还有很多其他的可能性，我真的被困在这个问题上.在laravel中实现这种嵌套关系链接有那么难吗?

And many other possibilities, I'm really stuck on this. Is it so difficult in laravel to achieve this kind of nested relationship linking?

谢谢！

推荐答案

return Event::with('city.companies.persons')->get();

如果您只想从 persons 表中选择某些字段，请使用:

If you only want to select certain fields from the persons table, use this:

return Event::with(['city.companies.persons' => function ($query) {
    $query->select('id', '...');
}])->get();

这篇关于Laravel 嵌套关系的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！