public async Task <int> DeleteProductFromSellBill(UpdateProductInBillRequest request)
        {
            var sellBill = await _context.ProductInSellBills.FindAsync(request.SellBillId, request.ProductId);

            _context.ProductInSellBills.Remove(sellBill);

            return(await _context.SaveChangesAsync());
        }
        public async Task <IActionResult> DeleteProductFromSellBill([FromForm] UpdateProductInBillRequest request)
        {
            if (!ModelState.IsValid)
            {
                return(BadRequest(ModelState));
            }
            var productInSellBill = await _sellService.DeleteProductFromSellBill(request);

            return(Ok(productInSellBill));
        }
        public async Task <int> AddProductIntoSellBill(UpdateProductInBillRequest request)
        {
            var SellBillCompleted = new ProductInSellBill()
            {
                ProductId  = request.ProductId,
                SellBillId = request.SellBillId
            };

            _context.ProductInSellBills.Add(SellBillCompleted);

            return(await _context.SaveChangesAsync());
        }