保存更新实体框架时出现MVC 3剃刀实体框架错误 [英] MVC 3 Razor Entity Framwork Error When Saving Update Entity Framework

问题描述

HI
我是MVC的新手，目前正在将MVC3与Entity Framwork一起使用.
我正在尝试编辑数据库中的记录，但是由于存在我无法修复的错误而无法进行.
以下是错误信息在执行此代码

HI
I am new to MVC, I am currently using MVC3 with Entity Framwork.
I am trying to Edit a record in my DB,but cannot due to an error that i cannot for the life of me fix.
Below is erro That is beeing thrown when excuting this lone of code

db.Tickets.Attach(ticket);

任何帮助将不胜感激.谢谢:)

具有相同键的对象已存在于ObjectStateManager中. ObjectStateManager无法使用相同的键跟踪多个对象.

Any assistance will be much appreciated. Thank you :)

An object with the same key already exists in the ObjectStateManager. The ObjectStateManager cannot track multiple objects with the same key.

[HttpPost]
        public ActionResult Edit(Ticket ticket)
        {
            if (ModelState.IsValid)
            {

                Ticket ticket1 = db.Tickets.Single(t => t.TicketID == ticket.TicketID);
                ticket.DateCreated = ticket1.DateCreated;
                db.Tickets.Attach(ticket);
                db.ObjectStateManager.ChangeObjectState(ticket, EntityState.Modified);
                db.SaveChanges();
                return RedirectToAction("Index");
            }
            //ViewBag.CategoryType_CategoryTypeID = new SelectList(db.CategoryTypes, "CategoryTypeID", "CategoryTypeDesc", ticket.CategoryType_CategoryTypeID);
            ViewBag.HighLevelCategory_HighLevelCategoryID = new SelectList(db.HighLevelCategories, "HighLevelCategoryID", "HighLevelCategoryDesc", ticket.HighLevelCategory_HighLevelCategoryID);
            ViewBag.Priority_PriorityID = new SelectList(db.Priorities, "PriorityID", "PriorityDesc", ticket.Priority_PriorityID);
            ViewBag.ServiceProvider_ServiceProviderID = new SelectList(db.ServiceProviders, "ServiceProviderID", "ServiceProviderName", ticket.ServiceProvider_ServiceProviderID);
            ViewBag.Site_SiteID = new SelectList(db.Sites, "SiteID", "SiteName", ticket.Site_SiteID);
            ViewBag.SubCategory_SubCategoryID = new SelectList(db.SubCategories, "SubCategoryID", "SubCategoryDesc", ticket.SubCategory_SubCategoryID);
            ViewBag.Status_TicketStatusID = new SelectList(db.TicketStatus, "TicketStatusID", "TicketStatusDesc", ticket.Status_TicketStatusID);
            return View(ticket);
        }

推荐答案

错误表示它的意思.在将项目添加到集合之前，请搜索集合以确保其不存在.如果要进行批量插入，则必须跟踪插入的内容，就像保留代表键的字符串或整数列表一样简单.不要插入两次.如果这样做，则会出现此错误.

The error means what it says. Before you add an item to the collection, search the collection to make sure it''s not there. If you''re doing a bulk insert, you must keep track of what you inserted, which is as easy as keeping a list of strings or ints that represents the keys. Don''t insert something twice. If you do, you get this error.

克里斯蒂安
感谢您的回应.

删除
时

Hi Christian
thanks for the response.

When removing

Ticket ticket1 = db.Tickets.Single(t => t.TicketID == ticket.TicketID);
                ticket.DateCreated = ticket1.DateCreated;

我在视图中添加了创建日期作为隐藏字段.
最初它返回为null.

i added date created to the view as a hidden field.
initially it was coming back as null.

@Html.HiddenFor(model => model.DateCreated)

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