Database Seeder Manager Skill

Use this skill to create or refactor Seeders, especially when moving from hardcoded data to JSON files or factories.

Core Rules

1. Idempotency (Run Multiple Times Safe)

• Seeders MUST be safe to run multiple times without creating duplicate dirty data.
• Use updateOrCreate or firstOrCreate based on a unique key (e.g., slug, email, code).

2. JSON Data Source Pattern

When populating data from JSON files (e.g., database/data/*.json):

1. Read File: Use file_get_contents and json_decode.
2. Iterate: Loop through the array.
3. Persist: Use updateOrCreate.

$json = file_get_contents(database_path('data/categories.json'));
$categories = json_decode($json, true);

foreach ($categories as $data) {
    Category::updateOrCreate(
        ['slug' => $data['slug']], // Unique Key
        [
            'name' => $data['name'],
            'description' => $data['description'] ?? null,
        ]
    );
}

3. Removing IDs

• Never force id from JSON unless it’s a critical system constant. Let the database Auto-Increment handle IDs.
• If relationships rely on specific “codes” in the JSON, look up the related ID by that code, do not hardcode the foreign ID.

4. Registration

• Always check if the Seeder is called in DatabaseSeeder.php. If not, register it.