Laravel Database: Seeding

Introduction
Laravel includes a simple method of seeding your database with test data using seed classes. All seed classes are stored in the database/seeds directory. Seed classes may have any name you wish, but probably should follow some sensible convention, such as UsersTableSeeder, etc. By default, a DatabaseSeeder class is defined for you. From this class, you may use the call method to run other seed classes, allowing you to control the seeding order.

Writing Seeders
To generate a seeder, execute the make:seeder Artisan command. All seeders generated by the framework will be placed in the database/seeds directory:

php artisan make:seeder UsersTableSeeder

A seeder class only contains one method by default: run. This method is called when the db:seed Artisan command is executed. Within the run method, you may insert data into your database however you wish. You may use the query builder to manually insert data or you may use Eloquent model factories.

use Illuminate\Database\Seeder;
use Illuminate\Support\Facades\DB;

class DatabaseSeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
        DB::table('users')->insert([
            'name' => str_random(10),
            'email' => str_random(10).'@gmail.com',
            'password' => bcrypt('secret'),
        ]);
    }
}

Using Model Factories
Of course, manually specifying the attributes for each model seed is cumbersome. Instead, you can use model factories to conveniently generate large amounts of database records. First, review the model factory documentation to learn how to define your factories. Once you have defined your factories, you may use the factory helper function to insert records into your database.

For example, let’s create 50 users and attach a relationship to each user:

public function run()
{
    factory(App\User::class, 50)->create()->each(function ($u) {
        $u->posts()->save(factory(App\Post::class)->make());
    });
}

Calling Additional Seeders
Within the DatabaseSeeder class, you may use the call method to execute additional seed classes. Using the call method allows you to break up your database seeding into multiple files so that no single seeder class becomes overwhelmingly large. Pass the name of the seeder class you wish to run:

public function run()
{
    $this->call([
        UsersTableSeeder::class,
        PostsTableSeeder::class,
        CommentsTableSeeder::class,
    ]);
}

Running Seeders
Once you have written your seeder, you may need to regenerate Composer’s autoloader using the dump-autoload command:

composer dump-autoload

Now you may use the db:seed Artisan command to seed your database. By default, the db:seed command runs the DatabaseSeeder class, which may be used to call other seed classes. However, you may use the –class option to specify a specific seeder class to run individually:

php artisan db:seed

php artisan db:seed –class=UsersTableSeeder
You may also seed your database using the migrate:refresh command, which will also rollback and re-run all of your migrations. This command is useful for completely re-building your database:

php artisan migrate:refresh –seed