导航属性“SenderId”不是“对话”类型的声明属性答案

【问题标题】：The navigation property 'SenderId' is not a declared property on type 'Conversation'导航属性“SenderId”不是“对话”类型的声明属性
【发布时间】：2012-11-26 05:40:11
【问题描述】：

当我尝试更新数据库时，我得到这个错误：

导航属性“SenderId”不是“对话”类型的声明属性。验证它没有被明确地从模型中排除，并且它是一个有效的导航属性。

编辑

我认为问题在于对话和用户之间的映射关系，因为对话和用户之间存在两个一对多关系，即对话有两个指向用户的外键

以下是用户和对话的连接方式：

用户：

public class User
{
    [Key]
    [HiddenInput(DisplayValue = false)]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid UserId { get; set; }

    public virtual ICollection<Conversation> ConversationSenders { get; set; }
    public virtual ICollection<Conversation> ConversationRecievers { get; set; }

对话：

public class Conversation
{
    [Key]
    [HiddenInput(DisplayValue = false)]
    public Guid ConversationId { get; set; }

    [ForeignKey("SenderId")]
    public Guid SenderId { get; set; }

    [ForeignKey("RecieverId")]
    public Guid RecieverId { get; set; }

    [InverseProperty("ConversationSenders")]
    public virtual User Sender { get; set; }

    [InverseProperty("ConversationRecievers")]
    public virtual User Reciever { get; set; }

}

这是完整的代码：

用户：

public class User
{
    [Key]
    [HiddenInput(DisplayValue = false)]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid UserId { get; set; }


    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid CollegeId { get; set; }

    public int RoleId { get; set; }

    [Required]
    [DataType(DataType.EmailAddress)]
    public string Email { get; set; }

    [Required]
    [DataType(DataType.Password)]
    public string Password { get; set; }

    [Required]
    public string Name { get; set; }

    [Required]
    public string Surname { get; set; }

    public string Gender { get; set; }

    //role

    public DateTime? DateOfBirth { get; set; }


    public string ImageURL { get; set; }

    [ForeignKey("CollegeId")]
    public virtual College College { get; set; }

    [ForeignKey("RoleId")]
    public virtual UserRole UserRole { get; set; }

    public virtual ICollection<Advert> Adverts { get; set; }
    public virtual ICollection<Competition> Competitions { get; set; }
    public virtual ICollection<Message> Messages { get; set; }
    public virtual ICollection<Conversation> ConversationSenders { get; set; }
    public virtual ICollection<Conversation> ConversationRecievers { get; set; }
    public virtual ICollection<UserOS> UserOses { get; set; }

对话：

public class Conversation
{
    [Key]
    [HiddenInput(DisplayValue = false)]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid ConversationId { get; set; }

    [ForeignKey("SenderId")]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid SenderId { get; set; }

    [ForeignKey("RecieverId")]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid RecieverId { get; set; }

    [InverseProperty("ConversationSenders")]
    public virtual User Sender { get; set; }

    [InverseProperty("ConversationRecievers")]
    public virtual User Reciever { get; set; }

    public virtual ICollection<Message> Messages { get; set; }
}

留言

 public class Message
{
    [Key]
    [HiddenInput(DisplayValue = false)]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid MessageId { get; set; }

    [HiddenInput(DisplayValue = false)]
    public Guid UserId { get; set; }

    [HiddenInput(DisplayValue = false)]
    public Guid ConversationId { get; set; }

    public string Text { get; set; }

    public bool? IsSeen { get; set; }


    [ForeignKey("UserId")]
    public virtual User ConversationSender { get; set; }

    [ForeignKey("ConversationId")]
    public virtual Conversation Conversation { get; set; }
}

【问题讨论】：

标签： .net entity-framework ef-code-first database-migration entity-framework-migrations

【解决方案1】：

[ForeignKey("SenderId")]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid SenderId { get; set; }

[ForeignKey("RecieverId")]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid RecieverId { get; set; }

这两行错误地标记了[DatabaseGenerated(DatabaseGeneratedOption.Identity)]属性。从属性中删除这两个属性。更正的版本应该是：

[ForeignKey("User")]    
public Guid SenderId { get; set; }

[ForeignKey("User")]   
public Guid RecieverId { get; set; }

【讨论】：

@ Behnam Esmaili Sender 和 Receiver 实际上是 User，从 Conversation 到 User 有两个一对多的连接，您可以在代码中查找它们，但我会在此处详细说明该部分，所以我阅读代码会更容易：用户public virtual ICollection<Conversation> ConversationSenders { get; set; } public virtual ICollection<Conversation> ConversationRecievers { get; set; }
@Behnam Esmail 对话[ForeignKey("SenderId")] public Guid SenderId { get; set; } [ForeignKey("RecieverId")] public Guid RecieverId { get; set; } [InverseProperty("ConversationSenders")] public virtual User Sender { get; set; } [InverseProperty("ConversationRecievers")] public virtual User Reciever { get; set; }
@hyperN 我已经编辑了 post.check 并告诉我解决了吗？

【解决方案2】：

我终于找到了解决方案，愚蠢的错误。在保护中应该是

    [ForeignKey("Sender"), Column(Order = 0)]

    public Guid SenderId { get; set; }

    [ForeignKey("Receiver"), Column(Order = 1)]

    public Guid ReceiverId { get; set; }

不是

[ForeignKey("SenderId"), Column(Order = 0)]
[ForeignKey("ReceiverId"), Column(Order = 1)]

之后我得到了错误：

“在表 'Conversations' 上引入 FOREIGN KEY 约束 'FK_dbo.Conversations_dbo.Users_ReceiverId' 可能会导致循环或多个级联路径。指定 ON DELETE NO ACTION 或 ON UPDATE NO ACTION，或修改其他 FOREIGN KEY 约束。无法创建约束。查看以前的错误。”

而解决方案是：在 DbContext 中这段代码：

        modelBuilder.Entity<Conversation>()
           .HasRequired(s => s.Sender)
           .WithMany(s => s.ConversationSenders)
           .HasForeignKey(s => s.SenderId)
           .WillCascadeOnDelete(false);


        modelBuilder.Entity<Conversation>()
            .HasRequired(r => r.Receiver)
            .WithMany(r => r.ConversationReceivers)
            .HasForeignKey(r => r.ReceiverId)
            .WillCascadeOnDelete(false);

我已经测试过了，现在一切正常 =)

【讨论】：