Question

• Firebird 2.5
• Entity Framework 5
• FirebirdClientDll 3.0.0.0

Hi, I’m trying to access my legacy database with the Entity Framework (Code First).
I got the problem that the database does not use foreign keys…

public class CUSTOMERS
{
    public int CUSTOMERID { get; set; }
    public string NAME{ get; set; }
}

public class INVOICES
{
    public int INVOICEID{ get; set; }
    public int CUSTOMERID{ get; set; }

    public virtual CUSTOMERS CUSTOMERS { get; set; }
}

public class INVOICEContext : DbContext
{
    public DbSet<CUSTOMERS> CUSTOMERS{ get; set; }
    public DbSet<INVOICES> INVOICES{ get; set; }

    public INVOICEContext(DbConnection connectionString) : base(connectionString, false)
    {
        Database.SetInitializer<INVOICEContext>(null);
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();

        /*modelBuilder.Entity<INVOICES>().HasRequired(b => b.CUSTOMERS)
                    .WithMany()
                    .Map(p => p.MapKey("INVOICEID"));*/ //Doesn't work because INVOICEID is defined

        modelBuilder.Entity<INVOICES>().HasKey(a => new { a.INVOICEID, a.CUSTOMERID});
        modelBuilder.Entity<CUSTOMERS>().HasKey(a => new { a.CUSTOMERID });

        base.OnModelCreating(modelBuilder);
    }
}

Normally I could remove the property CUSTOMERID from the class INVOICES, but in this case it is part of the primary key…

I found many threads which suggested to use IsIndependent, but it seems to be removed from the Entity Framework 5 (or 4.1).

I hope you can understand my poor English and maybe give me a hint what I’m doing wrong ^^

Answer 1

I don’t know what you mean with “the database does not use foreign keys“. So, maybe the following is not the answer you are looking for. But I’d say that you can use your relationship mapping that is commented out in your code if you replace ...MapKey... by HasForeignKey and use CUSTOMERID instead of INVOICEID as the foreign key property:

modelBuilder.Entity<INVOICES>()
    .HasRequired(b => b.CUSTOMERS)
    .WithMany()
    .HasForeignKey(b => b.CUSTOMERID);

The model and the rest of the mapping is fine in my opinion. Your relationship is an identifying relationship (that means that the foreign key is part of a composite primary key) which is a valid mapping with Entity Framework.