摘要：What it sounds like to me is that you're getting a user from one context, and attempting to delete from another.E.g.User myUser =null;using(MyData data =newMyData()){ myUser = data.GetUserById(1);} using(MyData data =newMyData()){ data.DeleteUser(myUser);}The 2nd "data" doesn't kno 阅读全文

摘要：EntityType 'BookInfo' has no key defined. Define the key for this EntityType建的模型需要有PK主关键字,默认为’Id’或者‘实体名Id'，如果PK不是这两个，要先添加[Key]到PK上方。具体查看本博客文章：http://www.cnblogs.com/llk8/category/545808.html 阅读全文

摘要：1、工具——》库程序包管理器——》管理解决方案的nuget程序包2、选中已安装的包，找到EntityFramework,点击管理，后面的你应该就清楚啦！当然我用的是VS2012，如果你的版本较低的话，可能需要先安装Nuget。可以先卸载再添加。最后看下引用里面有没有即可。 阅读全文