Entity Framework multiple navigation properties to the same table

Question

Entity Framework multiple navigation properties to the same table

ef-code-first entity-framework entity-framework-6

Question

I have a problem with EF Code First and I can't find how to solve it:

Let's say I have this two POCO:

public class DocumentRequest
{
    // Database Id
    public Guid Id { get; set; }

    // Origin
    public Guid OriginDocumentId { get; set; }
    public Document OriginDocument { get; set; }
    // Target
    public Guid TargetDocumentId { get; set; }
    public Document TargetDocument { get; set; }
}

public class Document
{
    // Database Id
    public Guid Id { get; set; }

    public string DocumentMessage {get; set;}

    public Guid? FromDocumentRequestId { get; set; }
    public DocumentRequest FromRequest { get; set; }

    public ICollection<DocumentRequest> SentDocumentRequests {get; set;}
}

When I create a DocumentRequest from one Document, I create a copy of the document and then a document request:

The original document will have a DocumentRequest added to the SentRequests navigation property

The copied document will have the FromDocumentRequestId pointing to the DocumentRequestId

How would you configure code first to do that?

JuChom

View more on Stack Overflow

Yuliam Chandra · Accepted Answer · 8/6/2014 7:25:37 PM

If I understand you correctly, here is the classes and configuration you need.

Classes

public class Document
{
    public Guid Id { get; set; }
    public string DocumentMessage { get; set; }
    public DocumentRequest FromRequest { get; set; }
    public ICollection<DocumentRequest> SentDocumentRequests { get; set; }
}
public class DocumentRequest
{
    // One Document to one DocumentRequest
    [Key, ForeignKey("Document")]
    public Guid DocumentId { get; set; }
    public Document Document { get; set; }
    public Guid OriginDocumentId { get; set; }
    public Document OriginDocument { get; set; }
}

DbContext

public class AppContext : DbContext
{
    public DbSet<Document> Documents { get; set; }
    public DbSet<DocumentRequest> DocumentRequests { get; set; }
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        // One Document to many SendDocumentRequests.
        modelBuilder.Entity<Document>()
            .HasMany(x => x.SentDocumentRequests)
            .WithRequired(x => x.OriginDocument)
            .HasForeignKey(x => x.OriginDocumentId)
            .WillCascadeOnDelete(false);
    }
}

Structure

Sample Data

Document (Id = 1) is inserted
Document (Id = 1) is copied then Document (Id = 2) is inserted
Document Request is inserted
- DocumentId = 2
- OriginDocumentId = 1
Document (Id = 1) is copied again then Document (Id = 3) is inserted
Document Request is inserted
- DocumentId = 3
- OriginDocumentId = 1

Result

Document

Id
1
2
3

Document Request

DocumentId OriginDocumentId
    2            1
    3            1

Entity Framework multiple navigation properties to the same table

Question

Fastest Entity Framework Extensions

Accepted Answer

Classes

DbContext

Structure

Sample Data

Result

Performance

Expression Evaluator

Related