Programming EF with Code First (二) Configuration for relationships

public class Destination
{
public int DestinationId { get; set; }
public string Name { get; set; }
public string Country { get; set; }
public string Description { get; set; }
public byte[] Photo { get; set; }
public List<Lodging> Lodgings { get; set; }
}

public class Lodging
{
public int LodgingId { get; set; }
public string Name { get; set; }
public string Owner { get; set; }
public bool IsResort { get; set; }
public decimal MilesFromNearestAirport { get; set; }
public Destination Destination { get; set; }
}

Specifying an optional one-to-many relationship

modelBuilder.Entity<Destination>()
.HasMany(d => d.Lodgings)
.WithOptional(l => l.Destination);