SeederHelper

The SeederHelper class is a helper that simplifies seeding database relations in Laravel seeders. It provides static methods to automatically attach related models to entities for various relation types.

• See also
  • API - SeederHelper

Usage

The SeederHelper class provides static methods for seeding different types of relations. It's typically used in Laravel database seeders to automatically populate relations after creating model instances.

Seeding HasMany Relations

Use seedHasMany to attach related models in a one-to-many relationship. This method attaches 1-3 unassigned related models to each entity.

<?php

namespace Database\Seeders;

use App\Helpers\SeederHelper;
use Database\Factories\PostFactory;
use Illuminate\Database\Seeder;

class PostSeeder extends Seeder
{
    public function run(): void
    {
        $entities = (new PostFactory)
            ->count(50)
            ->create();

        SeederHelper::seedHasMany($entities, 'comments');
    }
}

The method finds all unassigned related models (where the foreign key is null or 0) and randomly assigns them to the entities.

Seeding HasOne Relations

Use seedHasOne to attach a single related model in a one-to-one relationship. Only attaches if the entity doesn't already have the relation.

<?php

namespace Database\Seeders;

use App\Helpers\SeederHelper;
use Database\Factories\UserFactory;
use Illuminate\Database\Seeder;

class UserSeeder extends Seeder
{
    public function run(): void
    {
        $entities = (new UserFactory)
            ->count(50)
            ->create();

        SeederHelper::seedHasOne($entities, 'profile');
    }
}

Seeding BelongsTo Relations

Use seedBelongsTo to associate entities with parent models. This randomly distributes entities across available parent models (1-3 entities per parent).

<?php

namespace Database\Seeders;

use App\Helpers\SeederHelper;
use Database\Factories\PostFactory;
use Illuminate\Database\Seeder;

class PostSeeder extends Seeder
{
    public function run(): void
    {
        $entities = (new PostFactory)
            ->count(50)
            ->create();

        SeederHelper::seedBelongsTo($entities, 'user');
    }
}

Seeding BelongsToOne Relations (1:1 Inverse)

Use seedBelongsToOne when seeding the inverse side of a HasOne relation. This ensures a 1:1 constraint by only associating entities with parent models that don't already have the relation.

<?php

namespace Database\Seeders;

use App\Helpers\SeederHelper;
use Database\Factories\ProfileFactory;
use Illuminate\Database\Seeder;

class ProfileSeeder extends Seeder
{
    public function run(): void
    {
        $entities = (new ProfileFactory)
            ->count(50)
            ->create();

        // 'user' is the belongsTo relation, 'profile' is the hasOne relation on User
        SeederHelper::seedBelongsToOne($entities, 'user', 'profile');
    }
}

Seeding BelongsToMany Relations

Use seedBelongsToMany to attach related models in a many-to-many relationship. This method attaches 1-8 related models to each entity, using actual related model IDs from the database.

<?php

namespace Database\Seeders;

use App\Helpers\SeederHelper;
use Database\Factories\PostFactory;
use Illuminate\Database\Seeder;

class PostSeeder extends Seeder
{
    public function run(): void
    {
        $entities = (new PostFactory)
            ->count(50)
            ->create();

        SeederHelper::seedBelongsToMany($entities, 'tags');
    }
}

Combining Multiple Relations

You can seed multiple relations in a single seeder:

<?php

namespace Database\Seeders;

use App\Helpers\SeederHelper;
use Database\Factories\PostFactory;
use Illuminate\Database\Seeder;

class PostSeeder extends Seeder
{
    public function run(): void
    {
        $entities = (new PostFactory)
            ->count(50)
            ->create();

        // Seed multiple relations
        SeederHelper::seedBelongsTo($entities, 'user');
        SeederHelper::seedHasMany($entities, 'comments');
        SeederHelper::seedBelongsToMany($entities, 'tags');
    }
}

Error Handling

All methods throw InvalidArgumentException if:

• The relation does not exist on the entity model
• The relation type doesn't match the expected type (e.g., calling seedHasMany on a HasOne relation)

Make sure your models have the corresponding relation methods defined before using the seeder helper.