'int', 'shopping_user_id' => 'int', 'new_member_id' => 'int' ]; protected $fillable = [ 'pre_member_id', 'shopping_user_id', 'new_member_id' ]; public function pre_member() { return $this->belongsTo(User::class, 'pre_member_id'); } public function new_member() { return $this->belongsTo(User::class, 'new_member_id'); } public function shopping_user() { return $this->belongsTo(ShoppingUser::class); } }