How can I populate a FK field using EF Code First?

I have a class Mailout with a Status that loo开发者_高级运维ks like this:

public class Mailout
{
   public int Id {get; set; }
   public string Name {get; set; }
   public MailoutStatus Status { get; set; }
}
public class MailoutStatus
{
   public int Id { get; set; }
   public string Name { get; set;}
}

When I insert Mailouts and set the Status property, they are inserted correctly. When I fetch them, Status is always null. Since I don't have (and don't want) the status ID on my Mailout class, I have no way to retrieve it after-the-fact. How do I tell EF to populate this field eagerly, rather than lazily?

I'm hoping I can set something up in OnModelCreating() since I want this behavior all the time, not as an option that I can use sometimes by manipulating my LINQ-to-Entities queries.

You need to make your navigation properties virtual.

There is no such option in the ModelBuilder to configure an automatic eager loading of navigation properties in each query. You have to specify it query by query. As a workaround you could encapsulate eager loading in some method or property, for instance in the context:

public class MyContext : DbContext
{
    public DbSet<Mailout> Mailouts { get; set; }
    public IQueryable<Mailout> MailoutsWithStatus
    {
        get { return Mailouts.Include(m => m.Status); }
    }
    // ...
}

And then use in your queries:

context.MailoutsWithStatus.Where(...) ... etc.

Only an idea, it's untested.

Taking from Employee Info Starter Kit - upcoming MVC edition, here is a snippet, that works pretty well, to eager load objects when used:

public class Employee
{
    ...
    public int? ReportsTo { get; set; }

    [ForeignKey("ReportsTo")]
    public virtual Employee Supervisor { get; set; }

    /// <summary>
    /// Children object collection of foreign key relation 
    /// </summary>
    public virtual List<Employee> Subordinates { get; set; }
}