belongsTo(Warehouse::class); } public function unit() { return $this->belongsTo(Unit::class); } public static function adjustStock(int $warehouseId, int $unitId, bool $isBroken, float $quantity): void { $stock = self::firstOrCreate([ 'warehouse_id' => $warehouseId, 'unit_id' => $unitId, 'is_broken' => $isBroken, ], [ 'quantity' => 0, ]); $stock->increment('quantity', $quantity); } }