Laravel nested relationships

Question

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

Now the problem is there are some tables between the event and the person..

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 

Answer 1

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

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();

Answer 2

For city and companies specific fields , you need to distribute the with eloquent. Eg:

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

I created a HasManyThrough relationship for cases like this: Repository on GitHub

After the installation, you can use it like this:

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

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

You can get attributes from intermediate tables with withIntermediate() :

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

Answer 4

return Event::with(['city:id,name', 'city.companies:id,name', 'city.companies.persons:id,name'])->get();

Answer 5

To expand on @rashmi-nalwaya 's answer. I got it working for a 5.8 project with some tweaks.

My example was a bit different because I am trying to reference hasOne relations, rather than hasMany.

So for reference, Domains belong to one Website, which belongs to one Server. I only wanted to return certain columns from all of those tables. I had to do this.

Domain::with([
    'website' => function($q){
        $q->select('id', 'server_id');
    },
    'website.server' => function($q){
        $q->select('id', 'hostname', 'nickname');
    }
])
    ->select('id', 'website_id', 'domain')
    ->get();

Had to make sure I passed through the primary key for the table I'm on at any time (so the id in my case), and secondly, the foreign key of the related table I'm trying to get to. So website_id from domain, and server_id from website. Then it worked perfectly.

In my code I also have a further where clause on the main domain, after all this with-ness.

Answer 6

here is my project code, where I used this.

Checkout::where('cart_number', $cart_number)->with('orders.product')->first();

Result:

 "id": 23,
  "user_id": 4,
  "cart_number": "20219034",
  "phone_number": null,
  "mobile": "01533149024",
  "alternate_phone": "01533149024",
  "country_id": 19,
  "state_id": 750,
  "city_id": 8457,
  "address": "272/1-B, West Nakhalpara,Tejaon,Dhaka",
  "postal_code": "1215",
  "note": "dasd",
  "total": 974,
  "payment_type": "pending",
  "payment_status": 0,
  "courier_id": 3,
  "delivery_status": 0,
  "commented_by": null,
  "rating": null,
  "review": null,
  "coupon_code": null,
  "coupon_status": null,
  "created_at": "2021-10-09T14:59:46.000000Z",
  "updated_at": "2021-10-09T15:33:35.000000Z",
  "orders": [
    {
      "id": 32,
      "user_id": 4,
      "checkout_id": 23,
      "product_id": 2,
      "cart_number": 20219034,
      "courier_id": 3,
      "order_number": "202190340",
      "price": "554",
      "quantity": "1",
      "payment_type": "cod",
      "delivery_status": "pending",
      "created_at": "2021-10-09T14:59:46.000000Z",
      "updated_at": "2021-10-09T14:59:46.000000Z",
      "product": {
        "id": 2,
        "name": "Jasmine Bowers",
        "slug": "jasmine-bowers",
        "media_link": null,
        "description": null,
        "regular_price": 905,
        "sale_price": 554,
        "sku": "32312312",
        "have_stock": 1,
        "stock_quantity": 312,
        "stock_alert_quantity": 50,
        "weight": 5,
        "shipping_class_id": 1,
        "downloadable_file": null,
        "download_limit": null,
        "download_expiry": null,
        "short_description": null,
        "category": "[\"1\"]",
        "brand": 1,
        "tags": "[\"praesentium exceptur\"]",
        "product_image": "http://localhost/Bajaar/media/logo.png",
        "color": "[\"green\"]",
        "size": "[\"fugiat proident del\"]",
        "model": "[\"molestiae quia aute\"]",
        "other": "[\"corrupti enim illo\"]",
        "draft": 1,
        "uploaded_by": 1,
        "created_at": "2021-07-12T20:39:41.000000Z",
        "updated_at": "2021-07-12T20:39:41.000000Z"
      }
    }

Answer 7

for two level، in Event model

public function cities()
{
    return $this->belongsToMany(City::class)->with('companies');
}

Answer 8

This is a problem that many devs will come accross, for that purpose ; You can chain relationships in whereRelation clause to mimic joins eg

<\/blockquote>

   

     Hope it saves you the hustle.
<\/blockquote>"