HasOne create not updating foreign field - php

Question

I'm using Laravel and I'm trying to create a related record from an array using the method HasOne::create. It inserts the related record, but does not add a new id to main model's foreign field. What am I doing wrong?
Thx
$contact = new Contact();
$contact->company = $data['company'] ?? '';
$contact->comment = $data['comment'] ?? '';
$contact->save();
$contact->address()->create($data['address']);
...
var_dump($contact->address_id); exit();
The relations work fine, all fields specified. By ->get() methods they're returning correct models
var_dump result - null
Also, the $data['address'] contains valid data, specified as fillable at Address model and address_id is fillable for Contact model
UPD:
Contact class:
public function address()
{
return $this->hasOne(Address::class, 'id', 'address_id');
}
Address class:
public function contact()
{
return $this->belongsTo(Contact::class, 'id', 'address_id');
}
$data['address'] contains an array with ['raw' => 'someaddress'], raw field is in $fillable

Answer 1

There's a nice guide on Eloquent Relationships here.
Based on that I just tested the code below and it works fine (using Laravel 5.8)
Migration
<?php
use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;
class Cars extends Migration
{
public function up()
{
Schema::create('owners', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
$table->timestamps();
});
Schema::create('cars', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
$table->timestamps();
$table->integer('owner_id')->unsigned()->index()->nullable();
$table->foreign('owner_id')->references('id')->on('owners');
});
}
public function down()
{
Schema::drop('cars');
Schema::drop('owners');
}
}
Models
//App/Owner.php
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Owner extends Model
{
protected $fillable = ['name'];
public function car()
{
return $this->hasOne(Car::class);
}
}
//App/Car.php
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Car extends Model
{
protected $fillable = ['name'];
public function owner()
{
return $this->belongsTo(Owner::class);
}
}
Test
<?php
namespace Tests\Feature;
use App\Owner;
use Tests\TestCase;
class TestCars extends TestCase
{
/**
* A basic feature test example.
*
* #return void
*/
public function testExample()
{
$owner = new Owner(['name' => 'Jack']);
$owner->save();
$owner->car()->create(['name' => 'Nice Car']);
}
}
SQL
select * from cars;
------------
# id, name, created_at, updated_at, owner_id
'1', 'Nice Car', '2019-06-21 13:08:58', '2019-06-21 13:08:58', '1'
select * from owners
-------------
# id, name, created_at, updated_at
'1', 'Jack', '2019-06-21 13:08:58', '2019-06-21 13:08:58'