Laravel nested relationships
PhpMysqlDatabaseLaravelPhp Problem Overview
I'm having trouble getting a very-nested relationship to work correctly in laravel.
The wanted behaviour is as follows,
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..
This is the query that works!
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
These are my relations
Event Model
class Event extends Eloquent
{
protected $table = 'events';
public function city()
{
return $this->belongsTo('City');
}
}
City Model
class City extends Eloquent
{
protected $table = 'cities';
public function companies()
{
return $this->hasMany('Company');
}
public function event()
{
return $this->hasMany('Event');
}
}
Company Model
class Company extends Eloquent {
protected $table = 'companies';
public function persons()
{
return $this->hasMany('Person');
}
public function city()
{
return $this->belongsTo('City');
}
}
Person Model
class Person extends Eloquent
{
protected $table = 'persons';
public function company()
{
return $this->belongsTo('Company');
}
public function eventscore()
{
return $this->belongsToMany('Event', 'event_scores', 'person_id', 'event_id')
->withPivot('score')
->withTimestamps();
}
}
What I have tried
return Event::with('city')->with('company')->get();
and
return Event::with('city')
->whereHas('companies', function($query) use ($company_id){
$query->where('company_id', $company_id);
})->get();
And many other possibilities, I'm really stuck on this. Is it so difficult in laravel to achieve this kind of nested relationship linking?
Thanks!
Php Solutions
Solution 1 - Php
return Event::with('city.companies.persons')->get();
If you only want to select certain fields from the persons table, use this:
return Event::with(['city.companies.persons' => function ($query) {
$query->select('id', '...');
}])->get();
Solution 2 - Php
For city and companies specific fields , you need to distribute the with eloquent. Eg:
return Event::with([
'city' => function ($query) {
$query->select('id', '...');
},
'city.companies' => function ($query) {
$query->select('id', '...');
},
'city.companies.persons' => function ($query) {
$query->select('id', '...');
}
])->get();
Solution 3 - Php
return Event::with(['city:id,name', 'city.companies:id,name', 'city.companies.persons:id,name'])->get();
Solution 4 - Php
for two level، in Event model
public function cities()
{
return $this->belongsToMany(City::class)->with('companies');
}
Solution 5 - Php
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 $this->hasManyDeep(
Person::class,
[City::class, Company::class],
['id'],
['city_id']
)->withIntermediate(City::class, ['id', '...']);
}
Solution 6 - Php
To expand on @rashmi-nalwaya 's answer. I got it working for a 5.8 project with some tweaks.
My example was a bit different because I am trying to reference hasOne relations, rather than hasMany.
So for reference, Domains belong to one Website, which belongs to one Server. I only wanted to return certain columns from all of those tables. I had to do this.
Domain::with([
'website' => function($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.
Solution 7 - Php
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"
}
}
Solution 8 - Php
> This is a problem that many devs will come accross, for that purpose ; > You can chain relationships in whereRelation clause to mimic joins e.g
Payment::query()->whereRelation('orders.users',auth()->id());
> The relations can continue to be nested with dot notation. > Hope it saves you the hustle.