Entity Framework Many to Many Code FIrst

Question

I have the following (simplified) Classes:

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Data.Entity.ModelConfiguration.Conventions;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace EFTest
{
    public class TextContext : DbContext
    {
        public DbSet<People> People { get; set; }
        public DbSet<File> Files { get; set; }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();
        }
    }

    public class People
    {
        public People()
        {
            Files = new List<File>();
        }
        public int PeopleId { get; set; }
        public string Nombre { get; set; }
        public List<File> Files { get; set; }
    }

    public class File
    {
        public File()
        {
            Friends = new List<People>();
            Foes = new List<People>();
        }
        public Int16 FileId { get; set; }
        public List<People> Friends { get; set; }
        public List<People> Foes { get; set; }
    }
}

When the db is created I expect it to have a Joint table for people and files. But none was created, just the table People and the table Files.

The following is an image of the Entity Data Model

I Expected that the model to show a Many to Many relationship as each people may have many files and each file may have many people

I'm quite new with EF, I know I need to use the Fluent Api to configure the relation but so far all the code I have tried has failed.

Thanks for the help

Answer 1

Try setting your related entities with the virtual keyword so that EF can override and implement those navigation properties itself. Also, I tend to use interfaces for the properties instead on concrete classes. Your call...

public class People
{
    public People()
    {
        Files = new List<File>();
    }
    public int PeopleId { get; set; }
    public string Nombre { get; set; }
    public virtual ICollection<File> Files { get; set; }
}

public class File
{
    public File()
    {
        Friends = new List<People>();
        Foes = new List<People>();
    }
    public Int16 FileId { get; set; }
    public virtual ICollection<People> Friends { get; set; }
    public virtual ICollection<People> Foes { get; set; }
}