EF Code First: Many-to-many and one-to-many

Question

This is probably just because my knowledge with the EF Code First fluent API is lacking, but I\'m stumped.

I want to model the following:

• A Gro

Answer 1

Try this (untested):

public class Group 
{
    public int Id { get; set; }
    public string Name { get; set; }

    public virtual ICollection PrimaryUsers { get; set; }
    public virtual ICollection SecondaryUsers { get; set; } 
}

public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int PrimaryGroupId { get; set; }

    public virtual Group PrimaryGroup { get; set; }
    public virtual ICollection SecondaryGroups { get; set; }
}

public class Context : DbContext
{
    public DbSet Users { get; set; }
    public DbSet Groups { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        modelBuilder.Entity()
                    .HasRequired(u => u.PrimaryGroup)
                    .WithMany(g => g.PrimaryUsers)
                    .HasForeignKey(u => u.PrimaryGroupId)
                    .WillCascadeOnDelete(false);

        modelBuilder.Entity()
                    .HasMany(u => u.SecondaryGroups)
                    .WithMany(g => g.SecondaryUsers)
                    .Map(m => m.MapLeftKey("UserId")
                               .MapRightKey("GroupId")
                               .ToTable("SecondaryGroupAssignments"));
    }
}