Laravel嵌套关系

Question

我很难让一个非常嵌套的关系在Laravel中正常工作。

需要的行为如下，

我按ID选择一个事件，我想查看哪些人订阅了该事件。现在的问题是在事件和人之间有一些表。

这就是有效的查询！

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 

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

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

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

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

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

class Company extends Eloquent {

    protected $table = 'companies';

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

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

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();
    }
}

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，我真的被困在这上面了。在laravel中实现这种嵌套关系链接有那么难吗？

谢啦！

Answer 1

我为以下情况创建了一个Hasmanythrough关系:GitHub上的存储库

安装完毕后，可以这样使用:

class Event extends Model {
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function persons() {
        return $this->hasManyDeep(
            Person::class,
            [City::class, Company::class],
            ['id'],
            ['city_id']
        );
    }
}

您可以使用withIntermedia()从中间表中获取属性:

public function persons() {
    return $this->hasManyDeep(
        Person::class,
        [City::class, Company::class],
        ['id'],
        ['city_id']
    )->withIntermediate(City::class, ['id', '...']);
}

Answer 2

对于城市和公司的特定领域，你需要用口才来分发。例如:

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

Answer 3

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

如果只想从人员表中选择某些字段，请使用以下命令:

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