how to return data from server while performing CRUD operation if IsIdentity column is defined

var dataManager = ej.DataManager({ url: "/Home/DataSource", insertUrl: "/Home/Insert", updateUrl: "/Home/Update", DeleteUrl: "/Home/Delete", adaptor:"UrlAdaptor"});

        $("#Grid").ejGrid({

            dataSource: dataManager,

            allowPaging: true,

            editSettings: { allowEditing: true, allowAdding: true, allowDeleting: true },

            toolbarSettings:{showToolbar:true,toolbarItems:["add","edit","cancel","update","delete"]},

            columns: [

                    { field: "OrderID", isPrimaryKey: true, isIdentity:true, type:"number", headerText: "Order ID" },

                    { field: "EmployeeID", type:"number", headerText: 'Employee ID' },

                    { field: "Freight", type:"number", headerText: 'Freight', format: "{0:C}" },

                    { field: "CustomerID",type:"string",headerText: 'Ship City' },

            ],

        });

@(Html.EJ().Grid<EditableOrder>("Grid")

                           .Datasource(ds => ds.URL(@Url.Action("DataSource")).UpdateURL("/Home/Update").InsertURL("/Home/Insert").RemoveURL("/Home/Delete")

                    .Adaptor(AdaptorType.UrlAdaptor))

                    .AllowPaging()

                    .Columns(col =>

                     {

                        col.Field(p => p.OrderID).IsPrimaryKey(true).IsIdentity(true).HeaderText("Order ID").Add();

                        col.Field(p => p.EmployeeID).HeaderText("Employee ID").Add();

                        col.Field(p => p.Freight).HeaderText("Freight").Format("{0:C2}").Add();

                        col.Field(p => p.CustomerID).HeaderText("Customer ID").TextAlign(TextAlign.Left).Add();

                     })

            )

  public ActionResult Insert(EditableOrder value)

        {

            OrderRepository.Add(value);

            var data = OrderRepository.GetAllRecords();

            return Json(value, JsonRequestBehavior.AllowGet);

        }

public ActionResult Insert(EditableOrder value)

        {

            var data = OrderRepository.GetAllRecords().Last();

            value.OrderID = ++data.OrderID;

            OrderRepository.Add(value);

            return Json(value, JsonRequestBehavior.AllowGet);

        }