Question

I have 2 entities.

public class Foo
{
   public virtual int FooId {get; set; }
   public virtual IList<Bar> Bars { get; set; }
   public virtual DateTime Date { get; set; }
}

public class Bar
{
   public virtual int BarId { get; set;}
   public virtual byte[] Value { get; set; }
   public virtual DateTime Date { get; set; }
   public virtual IList<Foo> Foos { get; set; }
}

When I load Foo from the database by FooId, it is completely hydrated, when I navigate to Bar, it has the correct BarId and Date from the database, but Value is always a byte[0].

Why?

The database is a varbinary(300) column.

The value in the database if I do select * from Bar in Management Studio shows

BarId      Value            Date
 1      0x20CF30467ABD   10/19/2011

Thoughts?

My mapping:

public class FooConfiguration : EntityTypeConfiguration<Foo>
{
    public FooConfiguration()
    {
       ToTable("Foo");

       HasKey(m => m.FooId);
       Property(m => m.Date);

        HasMany(m => m.Bars)
                .WithMany(l => l.Foos)
                .Map(m =>
                         {
                             m.ToTable("FooBars");
                             m.MapLeftKey("FooId");
                             m.MapRightKey("BarId");
                         });
    }
}
public class BarConfiguration : EntityTypeConfiguration<Bar>
{
    public BarConfiguration()
    {
       ToTable("Bar");

       HasKey(m => m.BarId);
       Property(m => m.Value);
       Property(m => m.Date);

        HasMany(m => m.Foos)
                .WithMany(l => l.Bars)
                .Map(m =>
                         {
                             m.ToTable("FooBars");
                             m.MapLeftKey("BarId");
                             m.MapRightKey("FooId");
                         });
    }
}

Answer 1

I refactored your code a bit but I can’t see your problem.

public class Foo
{
    public Foo()
    {
        Bars = new List<Bar>();
    }

    #region Public Properties

    public virtual IList<Bar> Bars { get; set; }

    public virtual DateTime Date { get; set; }

    public virtual int FooId { get; set; }

    #endregion
}

public class Bar
{
    #region Public Properties

    public virtual int BarId { get; set; }

    public virtual DateTime Date { get; set; }

    public virtual IList<Foo> Foos { get; set; }

    public virtual byte[] Value { get; set; }

    #endregion
}

public class FooConfiguration : EntityTypeConfiguration<Foo>
{
    public FooConfiguration()
    {
        HasKey(m => m.FooId);

        HasMany(m => m.Bars)
                .WithMany(l => l.Foos)
                .Map(m =>
                    { 
                        m.ToTable("FooBars");
                        m.MapLeftKey(f => f.FooId, "FooId");
                        m.MapRightKey(b => b.BarId, "BarId");
                    });
    }
}
public class BarConfiguration : EntityTypeConfiguration<Bar>
{
    public BarConfiguration()
    {
        HasKey(m => m.BarId);
    }
}

When I do this I get the byte[] back from the database

using(var context = new FooBarContext())
        {
            var foo = new Foo();
            foo.Date = DateTime.Now;

            var bar = new Bar();
            bar.Date = DateTime.Now;
            bar.Value = UTF8Encoding.UTF8.GetBytes("string");

            foo.Bars.Add(bar);

            context.Foos.Add(foo);

            context.SaveChanges();
        }

        using(var context = new FooBarContext())
        {
            var foos = context.Foos.Where(f => f.FooId == 1).ToList();
        }

Make sure you are using the latest of EF.