belongsTo(\App\Models\Customer::class); } public function discount() { return $this->belongsTo(\App\Models\Discount::class); } public function invoice() { return $this->belongsTo(\App\Models\Invoice::class, 'invoice_id', 'id'); } public function payment() { return $this->belongsTo(\App\Models\Payment::class); } public function user() { return $this->belongsTo(\App\Models\User::class); } public function orderItem() { return $this->belongsToMany(\App\Models\InvoiceItem::class, 'order__order_item', 'order_id', 'invoice_item_id'); } public function orderItems() { return $this->hasMany(OrderItem::class, 'order_id'); } }