【The instance of entity type 'xxxx' cannot be tracked because another instance with the same key value for {'Id'} is already being tracked.】的更多相关文章

The instance of entity type 'xxxx' cannot be tracked because another instance with the same key value for {'Id'} is already being tracked.

一.问题描述 问题:The instance of entity type 'xxxx' cannot be tracked because another instance with the same key value for {'Id'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is atta…

The instance of entity type 'Menu' cannot be tracked because another instance with the same key value for {'Id'} is already being tracked.

这里记录一个在使用.net core中ef core执行数据库操作时遇到的问题: 我在代码中使用DbContext下的Update方法准备将更改后的数据像这样步到数据库: _context.Menus.Update(menu); 这是很常见的用法,但没想到一直报如下错误: The instance of entity type 'Menu' cannot be tracked because another instance with the same key value for {'Id'}…

EF 更新实体 The instance of entity type 'BabyEvent' cannot be tracked because another instance

加上AsNoTracking. 人不能两次踏入同一条河. 我 就踏入了.o(╥﹏╥)o…

The instance of entity type 'manager' cannot be tracked because another instance with the same key value for {'id'} is already being tracked. When attaching existing entities, ensure that only one ent

最近在用ASP.NET CORE时遇到一些问题,现记录下: 出现上述错误,即在更新实体数据时出现的错误 services.AddDbContext<StoreContext>(c => c.UseInMemoryDatabase(Guid.NewGuid().ToString()).UseQueryTrackingBehavior(QueryTrackingBehavior.NoTracking));…

[转] EF cannot be tracked because another instance of this type with the same key is already being tracked

本文转自:http://stackoverflow.com/questions/6033638/an-object-with-the-same-key-already-exists-in-the-objectstatemanager-the-object cannot be tracked because another instance of this type with the same key is already being tracked If you load the entity…

type parameters of <T>T cannot be determined; no unique maximal instance exists for type variable T with upper bounds int,java.lang.Object

今天在进行代码检查的时候出现下面的异常: type parameters of <T>T cannot be determined; no unique maximal instance exists for type variable T with upper bounds int,java.lang.Object 当时的第一感觉就是代码因为jdk版本太低引起的. 因为最后咨询了配置管理组的同事,确实发现是因为我本地jdk用的是1.7版本,而代码检查机器上用的是jdk1.6版本.因此出现了这…

The entity type XXX is not part of the model for the current context.

今天遇到了一个奇葩问题,虽然解决了,但还是一脸懵,先附赠一下别人的解决方案:https://www.cnblogs.com/zwjaaron/archive/2012/06/08/2541430.html(我是参考这篇文章解决的,但是问题不一样). 先描述一下我的问题吧: 我们的项目的发布流程是,本地开发完成,提交测试环境,测试完成,提交业务测试环境,最终上线.前情提要:我们的新版本开发完成了,但是测试时间充裕,我们就进行了下一个迭代的开发,作为一个严肃的开发者,自己已经经过了测试环境的自测.然…

Flask - 访问返回字典的接口报错：The view function did not return a valid response. The return type must be a string, tuple, Response instance, or WSGI callable, but it was a dict.

背景 有一个 Flask 项目,然后有一个路由返回的是 dict 通过浏览器访问,结果报错 关键报错信息 TypeError: 'dict' object is not callable The view function did not return a valid response. The return type must be a string, tuple, Response instance, or WSGI callable, but it was a dict. 意思是不能返回…

Entity Framework 6如何进行导航属性的筛选（context.Msg.First(t=>t.Id==1).Include(t=>t.MsgDetail)，筛选MsgDetail带条件）

问题: https://q.cnblogs.com/q/98333/ Msg表(Id,Content,IsDel).内有 virtual ICollection<MsgDetail> MsgDetails属性 MsgDetail表(Id,MsgId,SubContent,IsDel) 两者是一对多关系. 如何进行如下意思的的筛选? 若写这句伪代码: context.Msg.First(t=>t.Id==1).Include(t=>t.MsgDetail.Where(t=>t.…

The entity type <type> is not part of the model for the current context

这是在网站里遇到的一个错误,自动生成的不能手动添加, reference: http://stackoverflow.com/questions/19695545/the-entity-type-xxx-is-not-part-of-the-model-for-the-current-context When I created a strong view using the Quickfix context it blew up, because it was trying to associ…