MVC3.0数据插入有关问题，求指教，插入数据不成功

 [HttpPost]        public ActionResult Index(Orders order, FormCollection formcollection)        {            OrderLines orderline = new OrderLines();            OrderLineDetails orderlinedetail = new OrderLineDetails();            order.OrderId = System.DateTime.Now.ToString("yyMMddHHmmssffff");            orderline.OrderLineId = System.DateTime.Now.ToString("yyMMddHHmmssffff");            orderlinedetail.OrderLineDetailId = System.DateTime.Now.ToString("yyMMddHHmmssffff");            order.ShippingConsignee = Request.Form["consignee"].ToString();            order.ShippingPostCode = Request.Form["postcode"].ToString();            order.ShippingTel = Request.Form["tel"].ToString();            order.ShippingMobile = Request.Form["mobile"].ToString();            order.ShippingAddressInfo = Request.Form["address"].ToString();            order.ShippingProvince = Request.Form["province"];            order.ShippingCity = Request.Form["city"];            order.ShippingDistrict = Request.Form["district"];            order.ShippingMobile = Request.Form["mobile"].ToString();            order.ShippingPostCode = Request.Form["postcode"].ToString();            order.MemberEmail = Request.Form["email"];            order.Remark = Request.Form["fq"] + ",";            ViewData["oid"] = order.OrderId;            ViewProductDetail product = datacontext.GetProduct(Request.Form["productid"]);            orderline.Price = product.DetailPrice;            orderline.OrderId = order.OrderId;            orderlinedetail.OrderId = order.OrderId;            orderlinedetail.OrderLineId = orderline.OrderLineId;            orderlinedetail.ProductDetailCode = product.DetailCode;            orderlinedetail.ProductDetailName = product.DetailName;            orderlinedetail.Size = Request.Form["ringsize"];            if (Request.Form["Message1"] != "")            {                order.Remark += Request.Form["Message1"];            }            order.OrderFrom = "工行商城";            if (Request.Form["invoice_title"] != "")            {                order.InvoiceContent = Request.Form["invoice_title"];            }            UpdateModel(order);            datacontext.Add(order);            UpdateModel(orderline);            datacontext.Add(orderline);            UpdateModel(orderlinedetail);            datacontext.Add(orderlinedetail);            datacontext.Save();            return RedirectToAction("Details", "Order", new { orderid = order.OrderId });        }

 //添加订单        public void Add(Orders order)        {            using (DavidnileDataContext datacontext = new DavidnileDataContext())            {                datacontext.Orders.InsertOnSubmit(order);            }        }        //添加订单信息        public void Add(OrderLines orderline)        {            using (DavidnileDataContext datacontext = new DavidnileDataContext())            {                datacontext.OrderLines.InsertOnSubmit(orderline);            }        }        //添加详细订单信息        public void Add(OrderLineDetails orderlinedetail)        {            using (DavidnileDataContext datacontext = new DavidnileDataContext())            {                datacontext.OrderLineDetails.InsertOnSubmit(orderlinedetail);            }        }        //信息保存        public void Save()        {            using (DavidnileDataContext datacontext = new DavidnileDataContext())            {                datacontext.SubmitChanges();            }        }