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EF problems with navigation and display properties

In the beginning I wanted to mention that I have been struggling with this thing for several days and have tried to answer many of the answers more or less related to this issue. But I couldn't solve it.

I have two classes that represent tables in a DB. These are the existing tables used by the old application and I cannot change them.

A message can contain multiple MessageRecipients.

Environment: MVC3, EF4.1

Classes:

public class Message
{
    [ForeignKey("MessageReciepients")]
    public virtual int MessageID { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }
    public DateTime Recieved { get; set; }
    [ForeignKey("User")]
    public int AuthorUserID { get; set; }

    //P\\ Navigation properties
    public virtual IList<MessageRecipient> MessageReciepients { get; set; }
    public virtual User User { get; set; }
}

public class MessageRecipient
{
    //[Key]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int MessageID { get; set; }
    public int UserID { get; set; }
    public bool Read { get; set; }
    public bool Important { get; set; }
    public bool Deleted { get; set; }
    public bool Destroyed { get; set; }

    //P\\ Navigation Properties
    public virtual User User { get; set; }
}

I have an error:

Foreign Key Component 'MessageID' is not a declared property in type "MessageRecipient". Make sure that it has not been explicitly excluded from the model and that it is a valid primitive property.

How do I correctly map these classes, relationships to load message recipients?

I can add that the navigation property User is working correctly for the post and is loading user data correctly.

I am not too experienced with .NET and I find out when I do this. I tried the EF API config to map these I tried to swear it, curse it and be close to crying and praying at the same time. No joy!

I am very grateful for the help.

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2 answers


It turned out that the problem was related to the composite key that I need to use, and this can all be solved with some attributes:

This is how it looks now:



public class Message
{
    public int MessageID { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }
    public DateTime Recieved { get; set; }

    [ForeignKey("User")]
    public int AuthorUserID { get; set; }

    //P\\ Navigation properties
    public virtual ICollection<MessageRecipient> MessageRecipients { get; set; }
    public virtual User User { get; set; }
}

public class MessageRecipient
{
    [Key, Column(Order=0), ForeignKey("User")]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int UserID { get; set; }

    [Key, Column(Order = 1)]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int MessageID { get; set; }

    public bool Read { get; set; }
    public bool Important { get; set; }
    public bool Deleted { get; set; }
    public bool Destroyed { get; set; }

    //P\\ Navigation Properties
    public virtual User User { get; set; }
}
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fill in the missing properties:



public class Message 
{
    public int MessageID { get; set; }
}

public class MessageRecipient 
{
    public int MessageID { get; set; }

    [ForeignKey("MessageID")]
    public Message Message { get; set; }
}
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