public IResult Add(Rental rental) { var result = _rentalDal.UserFindex(x => x.Id == rental.CustomerId); var result2 = _rentalDal.CardFindex(x => x.CarId == rental.CarId); if (result.Data > result2.Data) { _rentalDal.Add(rental); return(new SuccessResult(Messages.RentalAdd)); } else { return(new ErrorResult(Messages.NotFindex)); } }