DbEntityValidationException升级到EF 4.1后

Question

今天我决定升级到EF 4.1（来自CTP5）。我使用Code First。不幸的是，每当我试图运行项目我得到这个异常：

System.Data.Entity.Validation.DbEntityValidationException： 验证失败的一个或多个 实体。有关更多详细信息，请参阅“EntityValidationErrors” 属性。

EntityValidationErrors属性没有真正地说出任何有关导致异常的实体。虚空实际上是堆栈跟踪。但是，在Seed（）覆盖（在初始化程序类中）内部的context.SaveChanges（）行中引发了异常。

经过一些调试和注释掉一些代码后，我认为这与User，Item和Rating类有关。下面是这些类的代码：

public class User 
{ 
public int Id { get; set; } 
public string Nickname { get; set; } 
public string FirstName { get; set; } 
public string LastName { get; set; } 
public string Email { get; set; } 
public string Password { get; set; } 
public float Credits { get; set; } 
public float PromotionalCredits { get; set; } 
public string Telephone { get; set; } 
public string Mobile { get; set; } 
public double RatingAverage { get; set; } 
public string ProfileImage { get; set; } 
public int? DefaultAddressId { get; set; } 
[ForeignKey("DefaultAddressId")] 
public virtual Address DefaultAddress { get; set; } 
public virtual ICollection<Address> Addresses { get; set; } 
public virtual ICollection<Role> Roles { get; set; } 
public virtual ICollection<Comment> Comments { get; set; } 
public virtual ICollection<Item> Items { get; set; } 
public virtual ICollection<Bid> Bids { get; set; } 
public virtual ICollection<CreditCard> CreditCard { get; set; } 
public virtual ICollection<Message> ReceivedMessages { get; set; } 
public virtual ICollection<Message> SentMessages { get; set; } 
public virtual ICollection<Item> WatchList { get; set; } 
public virtual ICollection<Item> ViewList { get; set; } 
public virtual ICollection<Rating> OwnRatings { get; set; } 
public virtual ICollection<Rating> RatingsForOthers { get; set; } 
} 

public class Item 
{ 
public int Id { get; set; } 
public string Title { get; set; } 
public string Description { get; set; } 
public float StartingPrice { get; set; } 
public float? BidIncrement { get; set; } 
public DateTime StartDate { get; set; } 
public DateTime EndDate { get; set; } 
public int Status { get; set; } 
[ForeignKey("Status")] 
public virtual ItemStatus ItemStatus { get; set; } 
public virtual Address PickupAddress { get; set; } 
public virtual User User { get; set; } 
public virtual ChildCategory Category { get; set; } 
public virtual ICollection<Comment> Comments { get; set; } 
public virtual ICollection<Image> Images { get; set; } 
public virtual ICollection<Bid> Bids { get; set; } 
public virtual ICollection<User> WatchingUsers { get; set; } 
public virtual ICollection<User> ViewingUsers { get; set; } 
public virtual ICollection<Tag> Tags { get; set; } 
} 

这里的地方我使用的种子增加一些测试数据到数据库的代码（）重写：

var user1 = new User 
    { 
    FirstName = "John", 
    LastName = "Smith", 
    Nickname = "J.Smith", 
    Email = "[email protected]", 
    Password = "myPassword", 
    Mobile = "01542367", 
    Telephone = "824225523", 
    ViewList = new List<Item>(), 
    WatchList = new List<Item>(), 
    ReceivedMessages = new List<Message>(), 
    SentMessages = new List<Message>(), 
    Roles = new List<Role>(), 
    RatingsForOthers = new List<Rating>(), 
    OwnRatings = new List<Rating>(), 
    Bids = new List<Bid>(), 
    Credits = 600, 
    PromotionalCredits = 20, 
    ProfileImage = "http://localhost/Content/images/temp/default_profile.jpg", 
    Comments = new List<Comment>(), 
    Addresses = new List<Address> 
              { 
               new Address 
                { 
                 Area = (from c in districts.ElementAt(2).Cities.ElementAt(0).Areas 
                    where c.GoogleName.Equals("Sirhmoul") 
                    select c).First(), 
                 Details = "my address in the street", 
                 Name = "Home Address" 
                } 
              } 
}; 


     var add1 = (from c in user1.Addresses 
     where c.Name.Equals("Home Address") 
     select c).First(); 


     var item1 = new Item 
     { 
     Title = "HTC Desire", 
     Description = "Lorem Ipsum is simply dummy text", 
     StartingPrice = 400f, 
     User = user1, 
     EndDate = DateTime.Now.AddDays(10), 
     StartDate = DateTime.Now, 
     BidIncrement = 3f, 
     Status = 1, 
     Bids = new List<Bid>(), 
     Comments = new List<Comment>(), 
     PickupAddress = add1, 
     Images = new List<Image> 
     { 
     new Image 
      { 
      Description = "some image description", 
      Path = "http://localhost:2732/images/temp/dummyItem.png", 
      Rank = 1 
      }, 
      new Image 
      { 
      Description = "some image2 description", 
      Path = "http://localhost:2732/Content/images/temp/dummyItem.png", 
      Rank = 2 
      }, 
      new Image 
      { 
      Description = "some image3 description", 
      Path = "http://localhost:2732/Content/images/temp/dummyItem.png", 
      Rank = 3 
      } 
     }, 
     ViewingUsers = new List<User>(), 
     WatchingUsers = new List<User>(), 
     Tags = new List<Tag>() 

     }; 


     var electronics = (from c in categories 
     where c.Name.Equals("Electronics") 
     select c).First(); 

     var cellPhones = (from c in electronics.Children 
     where c.Name.Equals("Cell Phones & PDA's") 
     select c).First(); 
     cellPhones.Items.Add(item1); 

UPDATE：（清洗代码并将其替换为更新后的版本）

现在我确定它实际上是添加抛出异常的项目的代码。我将创建一个项目的代码注释掉，并将User实例自己添加到上下文中，然后运行该项目，它工作得很好。那么，我在创建项目的代码中发生了什么？

注：我之前没有这个问题，在升级到4.1 EF

有什么建议？

谢谢。

Answer 1

最后，这里的解决这个问题：EF 4.1 RTW Change to Default MaxLength in Code First

Answer 2

我注意到你的标量属性没有标记为virtual，但是你的导航属性是。现在清晨为时太早，想知道为什么会产生你所描述的错误，但它可能值得改变，看看它是否有帮助。