Entity Framework - The foreign key component … is not a declared property on type

问题

I have the following Model

public class FilanthropyEvent :  EntityBase, IDeleteable
{  
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTime EventDate { get; set; }
    public string Description { get; set; }
    public decimal Target { get; set; }
    public decimal EntryFee { get; set; }
    public bool Deleted { get; set; }

    public ICollection<EventAttendee> EventAttendees { get; set; }
}

public class Attendee : EntityBase, IDeleteable
{
    public int Id { get; set; }
    public string Email { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public bool MailingList { get; set; }
    public bool Deleted { get; set; }

    public ICollection<EventAttendee> EventAttendees { get; set; }
}

Events and Attendees is a many to many relationship but I needed another property on the association so I created an association entity

 public class EventAttendee : EntityBase
 {
    public int FilanthropyEventId { get; set; }
    public int AttendeeId { get; set; }
    public bool InActive { get; set; }

    public virtual Attendee Attendee { get; set; }
    public virtual FilanthropyEvent FilanthropyEvent { get; set; }
 }

These are the configurations for each FilanthropyEvent and Attendee

public class FilanthropyEventConfiguration : EntityTypeConfiguration<FilanthropyEvent>
{
       public FilanthropyEventConfiguration()
       {
           HasKey(x => x.Id);
           Property(x => x.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

           HasMany(x => x.EventAttendees).WithRequired(x =>      x.FilanthropyEvent).HasForeignKey(x => x.FilanthropyEvent);
       }
}

public AttendeeConfiguration()
{
        HasKey(x => x.Id);
        Property(x => x.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

        HasMany(x => x.EventAttendees).WithRequired(x => x.Attendee).HasForeignKey(x => x.AttendeeId);
}

public class EventAttendeesConfiguration : EntityTypeConfiguration<EventAttendee>
{
    public EventAttendeesConfiguration()
    {
        HasKey(x => new {x.FilanthropyEventId, x.AttendeeId});
    }
}

When I try and initialise the database via the update-database command in the package manager console I get the following error.

System.InvalidOperationException: The foreign key component 'FilanthropyEvent' is not a declared property on type 'EventAttendee'. Verify that it has not been explicitly excluded from the model and that it is a valid primitive property.

I realise I'm probably missing a mapping in the EventAttendeesConfiguration class but what would be the correct mapping to model this relationship?

回答1:

This code

HasMany(x => x.EventAttendees)
.WithRequired(x => x.FilanthropyEvent)
.HasForeignKey(x => x.FilanthropyEvent);

Should be

HasMany(x => x.EventAttendees)
.WithRequired(x => x.FilanthropyEvent)
.HasForeignKey(x => x.FilanthropyEventId);

来源：https://stackoverflow.com/questions/24785507/entity-framework-the-foreign-key-component-is-not-a-declared-property-on-typ

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