Laravel 8 Seeder Factory：在 null 上调用成员函数 count()

Question

当我开始使用 db:seed 为我的数据库播种时，我收到了这个错误：

  Call to a member function count() on null

  at P:\<folderName>\<folderName>\src\vendor\laravel\framework\src\Illuminate\Database\Eloquent\Factories\HasFactory.php:18
     14▕     {
     15▕         $factory = static::newFactory() ?: Factory::factoryForModel(get_called_class());
     16▕
     17▕         return $factory
  ➜  18▕                     ->count(is_numeric($parameters[0] ?? null) ? $parameters[0] : null)
     19▕                     ->state(is_array($parameters[0] ?? null) ? $parameters[0] : ($parameters[1] ?? []));
     20▕     }
     21▕
     22▕     /**

  1   P:\<folderName>\<folderName>\src\database\seeders\UserSeeder.php:23
      App\Models\UserPhoto::factory()

  2   P:\<folderName>\<folderName>\src\vendor\laravel\framework\src\Illuminate\Container\BoundMethod.php:36
      Database\Seeders\UserSeeder::run()

按照Documentation 中的示例，我尝试覆盖默认工厂，但没有帮助。

这是我的模型：

class UserPhoto extends Model
{
    use HasFactory;

    /**
     * Create a new factory instance for the model.
     */
    protected static function newFactory()
    {
        return UserPhotoFactory::new();
    }

}

如果我正常删除->has(UserPhoto::factory(1))Users 表种子

播种机：

class UserSeeder extends Seeder
{
    public function run()
    {
        $city = City::first();
        User::factory(15)
            ->for($city)
            ->has(UserPhoto::factory(1))
            ->create()
        ;

//        UserPhoto::factory();
    }
}

工厂：

class UserPhotoFactory extends Factory
{
    protected $model = UserPhoto::class;

    public function configure()
    {
        $this->afterCreating(function (UserPhoto $photo) {
            $height = $this->faker->numberBetween(100, 900);
            $width = $this->faker->numberBetween(100, 900);
            $contents = file_get_contents('www.placecage.com/c/'.$height.'/'.$width);
            $path = 'users/images/'.$photo->user_id.'/'.$photo->id.'.jpg';
            Storage::disk('local')->put($path, $contents);
        });
    }

    public function definition()
    {
        return [
//            'created_at' => Carbon::now()
        ];
    }
}

用户模型：

class User extends Authenticatable
{
    use HasFactory, Notifiable;

    protected $hidden = [
        'password',
    ];

    public function city() {
        return $this->belongsTo(City::class);
    }

    public function photos() {
        return $this->hasMany(UserPhoto::class);
    }
}

Answer 1

你的配置方法需要返回$this

https://github.com/laravel/framework/blob/8.x/src/Illuminate/Database/Eloquent/Factories/Factory.php#L171

Answer 2

尝试检查 City 模型中 UserPhoto 的关系名称，我假设您使用的是 userPhoto 所以我将它作为 has(UserPhoto::factory(), 'userPhoto') 中的第二个参数传递了

class UserSeeder extends Seeder
{
    public function run()
    {
        $city = City::first();
        User::factory(15)
            ->for($city)
            ->has(UserPhoto::factory(1), 'userPhoto')
            ->create()
        ;
    }
}