I wanted to insert few Article instances to my database when I was working on a Lumen Laravel project, each Article belongs to one Category and belongs to one User. These newly generated instances have to to be related to existent category_id and user_id values in the categories table and users table. so I found this simple trick and wanted to s…

Article.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Article extends Model
{

    use HasFactory;
    protected $fillable=['title','slug','description','link','category_id','user_id'];

    public function category(){
        return $this->belongsTo(Category::class,'category_id');
    }
    public function user()
    {
        return $this->belongsTo(User::class);
    }
}

ArticleFactory.php

<?php

namespace Database\Factories;

use App\Models\Article;
use App\Models\User;
user App\Models\Category;
use Illuminate\Database\Eloquent\Factories\Factory;

class ArticleFactory extends Factory
{
    protected $model = Article::class;

    public function definition(): array
    {
        return [
            'title' => $this->faker->unique()->sentence,
            'slug' => $this->faker->sentence,
            'description' => $this->faker->sentence,
            'link' => $this->faker->url,
            'category_id' => Category::all()->random()->id,
            'user_id' => User::all()->random()->id

        ];
        // TODO: Implement definition() method.
    }
}

Category.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
/**
@mixin Eloquent
 * Post
 *
 * @mixin Eloquent
 * */


class Category extends Model
{
    use HasFactory;
    
    protected $fillable =['name','slug'];
    public function articles()
    {
        return $this->hasMany(Article::class);
    }
}

User.php

<?php

namespace App\Models;

use Illuminate\Auth\Authenticatable;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Laravel\Lumen\Auth\Authorizable;

class User extends Model implements AuthenticatableContract, AuthorizableContract, JWTSubject
{
    use Authenticatable, Authorizable, HasFactory;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */

    protected $fillable = [
        'name', 'email','password', 'isAdmin'
    ];
    public function articles()
    {
        return $this->hasMany(Article::class);
    }
    /**
     * The attributes excluded from the model's JSON form.
     *
     * @var array
     */
    protected $hidden = [
        'password',
    ];

  
}