belongsTo(Customer::class, 'customer_id', 'id'); } public function order() { return $this->belongsTo(Order::class, 'order_sn', 'order_sn'); } public function creator() { return $this->belongsTo(Administrator::class, 'created_by', 'id'); } public function updater() { return $this->belongsTo(Administrator::class, 'updated_by', 'id'); } }