记录没有使用Asp.net Mvc

Question

我正在使用asp.net mvc创建一个简单的销售点系统。我们有销售和销售产品以及产品表。当完成的销售必须将数据保存到相关表中时，同时需要减少产品表的产品数量。但是只有一个转换有效，销售表才有效。其他人不起作用（销售产品和产品）。我在下面所做的一切。

     [HttpPost]
        public ActionResult SaveNew(string data)
        {      
            ajaxModel model = JsonConvert.DeserializeObject<ajaxModel>(data);
            bool status = false;
            try
            {
                using (aspposEntities1 db = new aspposEntities1())
                {
                    var sale = new sale
                    {  
                        subtotal = model.total,
                        pay = model.pay,
                        balance = model.balance
                    };

                    db.sales.Add(sale); 
                    db.SaveChanges();
                    model.data.ForEach( m =>
                    {
                        var db_product = db.products.First(e => e.id.ToString() == m.barcode_id.ToString());
                        db_product.qty = db_product.qty - m.qty;
                        db.sales_product.Add(new sales_product
                        {
                            sales_id = sale.id.ToString(),
                            barcode_id = m.barcode_id.ToString(),
                            price = m.pro_price,
                            qty = m.qty,
                            total = m.total_cost
                        });
                    });
                    db.SaveChanges();


                    status = true;
                }

                return new JsonResult { Data = new { status, message = "Entry saved successfully" } };

            }
            catch (Exception e)
            {
                return new JsonResult { Data = new { status, message = "There was an error saving the Entry" } };
            }

        }

tableview.cs

     public class tableView
        {
            public int barcode_id { get; set; }

            public string pname { get; set; }

            public int pro_price { get; set; }


            public int qty { get; set; }


            public int total_cost { get; set; }
        }


        public class ajaxModel
        {
            public List<tableView> data { get; set; }


            public int total { get; set; }

            public int pay { get; set; }

            public int balance { get; set; }
            public string orderid { get; set; }

        }


**product table**

     public partial class product
        {
            public int id { get; set; }
            public string proname { get; set; }
            public Nullable<int> cat_id { get; set; }
            public Nullable<int> brand_id { get; set; }
            public Nullable<int> qty { get; set; }
            public Nullable<int> price { get; set; }
        }

sales table

     public partial class sale
        {
            public int id { get; set; }
            public Nullable<int> subtotal { get; set; }
            public Nullable<int> pay { get; set; }
            public Nullable<int> balance { get; set; }
        }

sales product table

   public partial class sales_product
        {
            public int id { get; set; }
            public string sales_id { get; set; }
            public string barcode_id { get; set; }
            public Nullable<int> price { get; set; }
            public Nullable<int> qty { get; set; }
            public Nullable<int> total { get; set; }
        }**