SeederHelper

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

• See also
  • Backend - Seeder Helper

Class

<?php

namespace App\Helpers;

use Illuminate\Database\Eloquent\Collection;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\BelongsToMany;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Relations\HasOne;
use Illuminate\Support\Collection as SupportCollection;
use InvalidArgumentException;

class SeederHelper
{
    /**
     * Seed hasMany relations by attaching existing unassigned related models to entities.
     *
     * @param  Collection<int, Model>|SupportCollection<int, Model>|Model  $entities  Collection of entities or single entity to attach relations to
     * @param  string  $relation  Relation name on the entity model
     */
    public static function seedHasMany(Collection|SupportCollection|Model $entities, string $relation): void

    /**
     * Seed hasOne relations by attaching existing unassigned related models to entities.
     *
     * @param  Collection<int, Model>|SupportCollection<int, Model>|Model  $entities  Collection of entities or single entity to attach relations to
     * @param  string  $relation  Relation name on the entity model
     */
    public static function seedHasOne(Collection|SupportCollection|Model $entities, string $relation): void

    /**
     * Seed belongsTo relations by associating entities with existing parent models.
     *
     * @param  Collection<int, Model>|SupportCollection<int, Model>|Model  $entities  Collection of entities or single entity to associate with parents
     * @param  string  $relation  BelongsTo relation name on the entity model
     */
    public static function seedBelongsTo(Collection|SupportCollection|Model $entities, string $relation): void

    /**
     * Seed belongsTo relations for hasOne inverse (ensures 1:1 constraint).
     * Only associates entities with parent models that don't already have the relation.
     *
     * @param  Collection<int, Model>|SupportCollection<int, Model>|Model  $entities  Collection of entities or single entity to associate with parents
     * @param  string  $relation  BelongsTo relation name on the entity model
     * @param  string  $parentRelationName  The hasOne relation name on the parent model
     */
    public static function seedBelongsToOne(Collection|SupportCollection|Model $entities, string $relation, string $parentRelationName): void

    /**
     * Seed belongsToMany relations by attaching existing related models to entities.
     *
     * @param  Collection<int, Model>|SupportCollection<int, Model>|Model  $entities  Collection of entities or single entity to attach relations to
     * @param  string  $relation  Relation name on the entity model
     */
    public static function seedBelongsToMany(Collection|SupportCollection|Model $entities, string $relation): void
}

Methods

seedHasMany

• Type: (Collection|SupportCollection|Model $entities, string $relation) => void
• Description: Seeds hasMany relations by attaching existing unassigned related models to entities. For each entity, it randomly attaches 1-3 unassigned related models (or fewer if not enough are available).

Parameters:

• $entities - Collection of entities or a single entity to attach relations to
• $relation - Relation name on the entity model (must be a HasMany relation)

Example:

$users = User::factory()->count(50)->create();
SeederHelper::seedHasMany($users, 'posts');

seedHasOne

• Type: (Collection|SupportCollection|Model $entities, string $relation) => void
• Description: Seeds hasOne relations by attaching existing unassigned related models to entities. Only attaches if the entity doesn't already have the relation.

Parameters:

• $entities - Collection of entities or a single entity to attach relations to
• $relation - Relation name on the entity model (must be a HasOne relation)

Example:

$users = User::factory()->count(50)->create();
SeederHelper::seedHasOne($users, 'profile');

seedBelongsTo

• Type: (Collection|SupportCollection|Model $entities, string $relation) => void
• Description: Seeds belongsTo relations by associating entities with existing parent models. Randomly distributes entities across available parent models (1-3 entities per parent).

Parameters:

• $entities - Collection of entities or a single entity to associate with parents
• $relation - BelongsTo relation name on the entity model

Example:

$posts = Post::factory()->count(50)->create();
SeederHelper::seedBelongsTo($posts, 'user');

seedBelongsToOne

• Type: (Collection|SupportCollection|Model $entities, string $relation, string $parentRelationName) => void
• Description: Seeds belongsTo relations for hasOne inverse relations. Ensures a 1:1 constraint by only associating entities with parent models that don't already have the relation.

Parameters:

• $entities - Collection of entities or a single entity to associate with parents
• $relation - BelongsTo relation name on the entity model
• $parentRelationName - The hasOne relation name on the parent model

Example:

$profiles = Profile::factory()->count(50)->create();
SeederHelper::seedBelongsToOne($profiles, 'user', 'profile');

seedBelongsToMany

• Type: (Collection|SupportCollection|Model $entities, string $relation) => void
• Description: Seeds belongsToMany relations by attaching existing related models to entities. For each entity, it randomly attaches 1-8 related models (or fewer if not enough are available). Uses actual related model IDs from the database.

Parameters:

• $entities - Collection of entities or a single entity to attach relations to
• $relation - Relation name on the entity model (must be a BelongsToMany relation)

Example:

$posts = Post::factory()->count(50)->create();
SeederHelper::seedBelongsToMany($posts, 'tags');

Usage in Seeders

The SeederHelper is typically used in Laravel database seeders to automatically populate relations:

<?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($entities, 'comments');
        SeederHelper::seedBelongsToMany($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)