表拆分實體框架代碼優先-3個以上實體

Question

我在程序員中發布了一個問題： https : //softwareengineering.stackexchange.com/questions/315857/entity-framework-code-first-c-class-separation-and-eav

解決該問題的一種方法是在實體框架中進行表拆分。 到目前為止，我已經看到了如何使用2個實體執行此操作，但沒有使用3個或更多實體執行此操作。

以下是我要與之共享同一表的模型：

[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; }


    }

您看到的所有虛擬屬性均不具有List <>作為其類型，我希望它們共享同一張表（如果可能）。

[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; }
    }

我不知道為什么課程是局部的。 我一直在關注Internet上的一些教程，例如： http : //www.c-sharpcorner.com/UploadFile/ff2f08/table-splitting-in-entity-framework-6-code-first-approach/

我不能讓他們工作。

我什至在DbModelBuilder中嘗試過：

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);

        }

似乎沒有關於3個或更多實體映射的StackOverflow帖子。

當我嘗試運行它時，這是我得到的錯誤：

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

此答案來自ASP.NET論壇的Cole Wu： http : //forums.asp.net/p/2093110/6043922.aspx?p=True&t=635968548324560382

答案如下：

 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");



        }

解釋一下：

1. 不需要局部類（我之所以這樣說是因為有一個示例說明您需要局部類，但事實並非如此）：
2. 我還沒有測試過，但是對於要共享同一張表的所有類，我都使用了相同的鍵。
3. modelBuilder.Entity <= TheEntity將是您希望所有內容都映射到的主類。

4. 如果您使用的是ASP.NET Identity，並且是從IdentityDbContext擴展的（這是我的情況），則在OnModelCreating方法中包括base.OnModelCreating（modelBuilder）是非常重要的，否則，Identityissues會給您一個打擊，找不到IdenittyUser的主鍵。

   5. 然后，您將使用：

   modelBuilder.Entity.ToTable（“ MyTable”）modelBuilder.Entity.ToTable（“ MyTable”）modelBuilder.Entity.ToTable（“ MyTable”）

這會將Entity1，Entity2，Entity3等映射到MyTable。