如何映射实体框架CTP5中的多对多关系？ [英] How to map many-to-many relationships in Entity Framework CTP5?

问题描述

我正在尝试使用3个表（用户 - 接口表 - 语言）来映射2种类型（用户 - >语言），并且看起来像是modelBuilder正在期望这两种类型之间有一个引用（如user.languagesSpoken ，和language.UsersSpeaking）。所以基本上我可以建立一个像

modelBuilder.Entity< User>（）。HasMany（x => x.LanguagesSpoken）.WithMany（x => x.UsersSpeaking ）。

然而，我不需要从语言到用户的引用，并且无法弄清楚如何映射。

还有一种方法来指定一个连接表名称？

谢谢！

解决方案

做窍门：

  public class User 
 {
 public int UserId {get;组; } 
 public virtual ICollection< Language> LanguagesSpoken {get;组; } 
} 
 
 public class语言
 {
 public int LanguageId {get;组; } 
 public int Name {get;组; } 
} 
 
 public class上下文：DbContext 
 {
 public DbSet< User>产品{get;组; } 
 public DbSet< Language>语言{get;组; 
 
 protected override void OnModelCreating（ModelBuilder modelBuilder）
 {
 modelBuilder.Entity< User>（）
 .HasMany（x => x.LanguagesSpoken）
 .WithMany（）
 .Map（c => 
 {
 c.ToTable（yourDesiredName）; 
}）; 
} 
} 
  

I'm trying to map 2 types (user -> languages) using 3 tables (user - junction table - languages), and looks like the modelBuilder is expecting both types to have a reference to each other (like user.languagesSpoken, and language.UsersSpeaking). So basically I can build something like
modelBuilder.Entity<User>().HasMany(x=>x.LanguagesSpoken).WithMany(x=>x.UsersSpeaking).
I don't need a reference from language to user, however - and can't figure out how to map that..
Also, is there a way to specify a junction table name ?

Thanks!

解决方案

The following will do the trick:

public class User
{
    public int UserId { get; set; }
    public virtual ICollection<Language> LanguagesSpoken { get; set; }
}

public class Language
{
    public int LanguageId { get; set; }
    public int Name { get; set; }
}        

public class Context : DbContext
{
    public DbSet<User> Products { get; set; }
    public DbSet<Language> Languages { get; set; }        

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<User>()
                    .HasMany(x => x.LanguagesSpoken)
                    .WithMany()
                    .Map(c => 
                    { 
                        c.ToTable("yourDesiredName"); 
                    });
    }
}    

这篇关于如何映射实体框架CTP5中的多对多关系？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！