表拆分实体框架代码优先-3个以上实体

Question

I've posted a question in Programmers: https://softwareengineering.stackexchange.com/questions/315857/entity-framework-code-first-c-class-separation-and-eav

One solution to the problem is Table Splitting in Entity Framework. So far, I've seen how to do this with 2 entities, but not with 3 or more.

Here are the models I want to share a same table with:

[Table("Tournament")]
    public partial class PGTournament : IImageable
    {

        public int Id { get; set; }
        public string Name { get; set; }
        public GameGenre GameGenre { get; set; }
        public TournamentFormat TournamentFormat { get; set; }

        public TournamentStatus Status { get; set; } 
        public string Description { get; set; }
        public virtual List<PrizePool> Prizes { get; set; }

        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public virtual List<Participants.Participant> Participants { get; set; }
        public decimal Cost { get; set; }
        public string Streaming { get; set; }
        public int? ChallongeTournamentId { get; set; }
        public string Bracket { get; set; }
        public virtual List<TournamentMatch> Matches { get; set; }
        public int MainImageId { get; set; }
        public virtual Media MainImage { get; set; }
        public bool IsFollowUp { get; set; }
        public int? FollowUpTournamentId { get; set; }
        [ForeignKey("FollowUpTournamentId")]
        public virtual PGTournament FollowUptournament { get; set; }
        public int MediaID { get; set; }
        public int MainImageID { get; set; }

        //Properties that share same table:
        public virtual TournamentOrganizer Organizer { get; set; } //Change to Organizer
        public virtual TournamentOrganizerSetting OrganizerSetting { get; set; }
        public virtual TournamentSettings TournamentSettings { get; set; }
        public virtual TournamentRules Rules { get; set; }


    }

All the properties you see that are virtual and don't have a List<> as their type, I want them to share a same table (If it is possible).

[Table("Tournament")]
    public partial class TournamentOrganizer
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string UserId { get; set; }
        [ForeignKey("UserId")]
        public AppUser User { get; set; }

        public int LogoId { get; set; }
        [ForeignKey("LogoId")]
        public Media Logo { get; set; }
        public virtual TournamentOrganizerSetting Settings { get; set; }
        public virtual TournamentRules Rules { get; set; }
        public virtual TournamentSettings TournamentSettings { get; set; }
        public virtual PGTournament Tournament { get; set; }


    }

[Table("Tournament")]
    public partial class TournamentSettings
    {
        public int Id { get; set; }
        public string Address { get; set; }
        public string LocationGoogleMaps { get; set; }
        public bool isOnline { get; set; }
        public int MaxPlayers { get; set; }
        public List<TournamentAssistant> TournamentAssistants { get; set; }

        public virtual TournamentOrganizer Organizer { get; set; } //Change to Organizer
        public virtual TournamentRules Rules { get; set; }
        public virtual TournamentOrganizerSetting OrganizerSettings { get; set; }
        public virtual PGTournament Tournament { get; set; }

    }

 [Table("Tournament")]
    public partial class TournamentOrganizerSetting
    {
        public int Id { get; set; }
        public string Location { get; set; }
        //Properties that share same table:
        public virtual TournamentOrganizer Organizer { get; set; } //Change to Organizer
        public virtual TournamentRules Rules { get; set; }
        public virtual TournamentSettings TournamentSettings { get; set; }
        public virtual PGTournament Tournament { get; set; }
    }

 [Table("Tournament")]
    public partial class TournamentRules
    {
        public int Id { get; set; }
        public string Bans { get; set; }
        public string Allowed { get; set; }
        public string Description { get; set; }
        public string FileName { get; set; }
        public string FilePath { get; set; }

        //Properties that share same table:
        public virtual TournamentOrganizer Organizer { get; set; } //Change to Organizer
        public virtual TournamentOrganizerSetting OrganizerSetting { get; set; }
        public virtual TournamentSettings TournamentSettings { get; set; }
        public virtual PGTournament Tournament { get; set; }
    }

I don't know why the classes are partial. I've been following several tutorials over the Internet, such as this: http://www.c-sharpcorner.com/UploadFile/ff2f08/table-splitting-in-entity-framework-6-code-first-approach/

I can't get them to work.

I have even tried this in the DbModelBuilder:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {    
            modelBuilder.Entity<PGTournament>().ToTable("Tournament");


            modelBuilder.Entity<PGTournament>()
                .HasKey(e => e.Id)
                .HasOptional(e => e.FollowUptournament)
                .WithMany();

            modelBuilder.Entity<PGTournament>()
                .HasKey(e => e.Id)
                .HasRequired(e => e.Organizer)
                .WithRequiredDependent(e => e.Organizer)

            modelBuilder.Entity<TournamentOrganizer>()
                .HasKey(e => e.Id)
                .HasRequired(e => e.Settings)
                .WithRequiredDependent(e => e.Organizer);

            modelBuilder.Entity<TournamentViewModel>()
                .HasKey(e => e.Id)
                .HasRequired(e => e.Settings)
                .WithRequiredDependent(e => e.Organizer);


            modelBuilder.Entity<TournamentOrganizer>().Map(m => m.ToTable("Tournament"));
            modelBuilder.Entity<TournamentOrganizerSetting>().Map(m => m.ToTable("Tournament"));

            base.OnModelCreating(modelBuilder);

        }

There doesn't seem to be a StackOverflow post with Mapping to 3 or more entities.

When I try to run it, this is the error I get:

One or more validation errors were detected during model generation:

Pro_Gaming.Infrastructure.IdentityUserLogin: : EntityType 'IdentityUserLogin' has no key defined. Define the key for this EntityType.
Pro_Gaming.Infrastructure.IdentityUserRole: : EntityType 'IdentityUserRole' has no key defined. Define the key for this EntityType.
IdentityUserLogins: EntityType: EntitySet 'IdentityUserLogins' is based on type 'IdentityUserLogin' that has no keys defined.
IdentityUserRoles: EntityType: EntitySet 'IdentityUserRoles' is based on type 'IdentityUserRole' that has no keys defined.

Answer 1

This answer comes from Cole Wu from ASP.NET forums: http://forums.asp.net/p/2093110/6043922.aspx?p=True&t=635968548324560382

The answer is the following:

 protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            //Do not delete this:
            base.OnModelCreating(modelBuilder);

            modelBuilder.Entity<Tournament>()
                .HasKey(e => e.TournamentId)
                .HasRequired(e => e.Rules)
                .WithRequiredPrincipal();

            modelBuilder.Entity<Tournament>()
                .HasKey(e => e.TournamentId)
                .HasRequired(e => e.TournamentSettings)
                .WithRequiredDependent();

            modelBuilder.Entity<TournamentOrganizer>()
                .HasKey(e => e.Id)
                .HasRequired(e => e.Settings)
                .WithRequiredDependent();


            modelBuilder.Entity<Tournament>().ToTable("Tournament");
            modelBuilder.Entity<TournamentRules>().ToTable("Tournament");
            modelBuilder.Entity<TournamentSettings>().ToTable("Tournament");

            modelBuilder.Entity<TournamentOrganizer>().ToTable("TournamentOrganizer");
            modelBuilder.Entity<TournamentOrganizerSetting>().ToTable("TournamentOrganizer");



        }

Explaining a bit:

1. There is no need for partial classes (I say this because there is an example that states that you need partial classes, this is not true):
2. I haven't tested this, but I used the same key for all the classes that I wanted to share the same table.
3. modelBuilder.Entity <= TheEntity will be the main class you want everything mapped to.

4. If you are using ASP.NET Identity and you are extending from IdentityDbContext (which is my case), It is very important to include base.OnModelCreating(modelBuilder) in the OnModelCreating method, otherwise you'll be hit with Identityissues that it doesn't find the primary key for IdenittyUser.

   5. You would then use:

   modelBuilder.Entity.ToTable("MyTable") modelBuilder.Entity.ToTable("MyTable") modelBuilder.Entity.ToTable("MyTable")

This will map Entity1, Entity2, Entity3, etc to MyTable.