Entity Framework Code first creates unexpected Tables and Relationships - entity-framework

Question

Using EntityFramework 6.1.3, I've got the following
public class RacesContext:DbContext
{
public DbSet<Race> Races { get; set; }
public DbSet<Sailboat> Sailboats { get; set; }
public DbSet<VenueParticipation> VenueParticipations { get; set; }
}
public class Crew
{
public int CrewId { get; set; }
public string Name { get; set; }
}
public class Sailboat
{
[Key]
public int SailboatId { get; set; }
public string Name { get; set; }
public string Skipper { get; set; }
public virtual ICollection<Crew> BoatCrew { get; set; }
}
public class VenueParticipation
{
[Key]
public int Id { get; set; }
public virtual ICollection<Sailboat> Boats { get; set; }
public virtual ICollection<Race> Races { get; set; }
}
public class Race
{
[Key]
public int RaceId { get; set; }
public string Venue { get; set; }
public DateTime Occurs { get; set; }
}
EF creates the Creates the Crews table with the proper PK and FK as I would expect. But creates the Races Sailboats, VenueParticipations tables in an unexpected way. Sailboats get's the expected PK but the unexpected FK VenueParticipation_Id as does Races. I was expecting the VenueParticipations table to get FKs to the others allowing a many to many relationship.. I'm sure I'm missing something here. Any advice would be great.

Answer 1

You can either configure the joining tables VenueParticipationSailboat, VenueParticipationRace with the proper FKs or you can use the fluent API:
modelBuilder.Entity<VenueParticipation>()
.HasMany(t => t.Sailboats)
.WithMany(t => t.VenueParticipations)
.Map(m =>
{
m.ToTable("VenueParticipationSailboat");
m.MapLeftKey("VenueParticipationID");
m.MapRightKey("SailboatID");
});
https://msdn.microsoft.com/en-us/data/jj591620.aspx#ManyToMany