實體框架 - 配置識別密鑰

我具有以下類（每個字典可具有0,1或許多對象）：

public class Dictionary 
{ 
    public virtual ICollection<DictionaryDomain> Domains { get; set; } 
    public virtual int Id { get; set; } 
    public virtual string Name { get; set; } 
} 

public class DictionaryDomain 
{ 
    public virtual Dictionary Dictionary { get; set; } 
    public virtual int DictionaryId { get; set; } // I have added this after error described below 
    public virtual Domain Domain { get; set; } 
    public virtual int Id { get; set; } 
} 

public class Domain 
{ 
    public virtual int Id { get; set; } 
    public virtual string Name { get; set; } 
}

當我刪除域（僞碼）

Dictionary d = GetDictionary(); 
d.Domains.remove(some_object);

我得到一個錯誤：

A relationship from the 'DictionaryDomain_Dictionary' AssociationSet is in the 'Deleted' state. Given multiplicity constraints, a corresponding 'DictionaryDomain_Dictionary_Source' must also in the 'Deleted' state.

因此，我已將DictionaryId添加到類作爲重點，並配置類的部分是這樣的：

 modelBuilder.Entity<Dictionary>() 
      .HasKey(e => e.Id); 
     modelBuilder.Entity<Dictionary>() 
      .Property(e => e.Name).IsRequired().HasMaxLength(200); 

     modelBuilder.Entity<DictionaryDomain>() 
      .HasRequired(e => e.Dictionary); 
      // Added from this line 
     modelBuilder.Entity<DictionaryDomain>() 
      .HasKey(e => new { e.Id, e.DictionaryId }); 
     modelBuilder.Entity<DictionaryDomain>() 
      .Property(e => e.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity); 
     modelBuilder.Entity<DictionaryDomain>() 
      .Property(e => e.DictionaryId).HasColumnName("Dictionary_Id"); 
      // Till this line 
     modelBuilder.Entity<DictionaryDomain>() 
      .HasRequired(e => e.Domain); 

     modelBuilder.Entity<Domain>() 
      .HasKey(e => e.Id); 
     modelBuilder.Entity<Domain>() 
      .Property(e => e.Name).IsRequired().HasMaxLength(200);

但之後我加入我得到了一些奇怪的移民遷移：

public override void Up() 
    { 
     DropIndex("dbo.DictionaryDomains", new[] { "Domain_Id" }); 
     DropColumn("dbo.DictionaryDomains", "Id"); 
     RenameColumn(table: "dbo.DictionaryDomains", name: "Domain_Id", newName: "Id"); 
     DropPrimaryKey("dbo.DictionaryDomains"); 
     AlterColumn("dbo.DictionaryDomains", "Id", c => c.Int(nullable: false, identity: true)); 
     AddPrimaryKey("dbo.DictionaryDomains", new[] { "Id", "Dictionary_Id" }); 
     CreateIndex("dbo.DictionaryDomains", "Id"); 
    }

這不是我所期待的（我的預期只有主鍵的娛樂）。

我不知道我做錯了什麼。也許我沒有足夠的瞭解EF如何工作，但任何提示將不勝感激。

感謝

來源

2015-09-04 rrejc

解決方案是DomainId添加到類，而這個字段添加到複合鍵。

類看起來是這樣的：

public class DictionaryDomain 
{ 
    public virtual Dictionary Dictionary { get; set; } 
    public virtual int DictionaryId { get; set; } 
    public virtual Domain Domain { get; set; } 
    public virtual int DomainId { get; set; } 
    public virtual int Id { get; set; } 
}

和映射：

 modelBuilder.Entity<DictionaryDomain>() 
      .HasRequired(e => e.Dictionary); 
     modelBuilder.Entity<DictionaryDomain>() 
      .HasKey(e => new {e.Id, e.DictionaryId, e.DomainId}); 
     modelBuilder.Entity<DictionaryDomain>() 
      .Property(e => e.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity); 
     modelBuilder.Entity<DictionaryDomain>() 
      .Property(e => e.DictionaryId).HasColumnName("Dictionary_Id"); 
     modelBuilder.Entity<DictionaryDomain>() 
      .Property(e => e.DomainId).HasColumnName("Domain_Id"); 
     modelBuilder.Entity<DictionaryDomain>() 
      .HasRequired(e => e.Domain);

後，我得到了正確的遷移：

 DropPrimaryKey("dbo.DictionaryDomains"); 
     AddPrimaryKey("dbo.DictionaryDomains", new[] { "Id", "Dictionary_Id", "Domain_Id" });

從集合中移除按預期工作後 - 爲現在:)

來源

2015-09-04 18:08:43 rrejc

實體框架 - 配置識別密鑰

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