实体框架多对多自引用 [英] Entity Framework many-to-many self-reference

问题描述

我有一个实体用户。每个用户应该有很多朋友和老师。使用EF代码首先我有点困惑如何实现我想要的。我看到自我参考的例子，但不是很多对。例如：

  public class Employee 
 {
 #region属性
 
 public int EmployeeID {get;组; } 
 public string FirstName {get;组; } 
 public string LastName {get;组; } 
 
 public int？ ManagerID {get;组; } 
 public Employee Manager {get;组; } 
 
 #endregion 
} 
  

和modelBuilder： / p>

  modelBuilder.Entity< Employee>（）。 
 HasOptional（e => e.Manager）。 
 WithMany（）。 
 HasForeignKey（m => m.ManagerID）; 
  

如何创建一个具有自我参考的实体，在我的情况下，有朋友（如果是朋友b这意味着b是a）和老师的朋友（如果a是b的老师，b是a的学生）？

对不起，如果已经存在类似的线程。
非常感谢任何帮助。

解决方案

好的，因为很多人回答这个;），我搜索再多一点，我找到了我的案例的解决方案。实体看起来像：

  public class User 
 {
 public int ID {get;组; } 
 public string UserName {get;组; } 
 
 public virtual ICollection< User>朋友{get;组; 
} 
  

modelBuilder：

$ b $ H $ M $（$）
.WithMany（）;

最后我做了帮助方法BeFriend和BecomeTeacher学习，这​​确保当你和某人成为朋友时成为你的朋友（以及教师学生的各自的东西）。

I have an entity User. Each User is supposed to have many Friends and Teachers. With EF Code First I am a little bit confused on how to achieve what I want. I saw examples of self reference, but not many-to-many. For example:

public class Employee
{
  #region Properties

  public int EmployeeID { get; set; }
  public string FirstName { get; set; }
  public string LastName { get; set; }

  public int? ManagerID { get; set; }
  public Employee Manager { get; set; }

  #endregion
}

and the modelBuilder:

modelBuilder.Entity<Employee>().
      HasOptional(e => e.Manager).
      WithMany().
      HasForeignKey(m => m.ManagerID);

How to create an entity with self-reference in my case, where there are Friends (if a is friend with b this means that b is friend with a) and Teachers (if a is teacher of b, b is student of a)?

Sorry if there already exists a similar thread. Any help is greatly appreciated.

解决方案

Ok, so because a lot of people answered this ;), I searched a little more and I found the solution for my case. The entity looks like:

public class User
{
    public int ID { get; set; }
    public string UserName { get; set; }

    public virtual ICollection<User> Friends { get; set; }
}

The modelBuilder:

modelBuilder.Entity<User>()
                .HasMany(x => x.Friends)
                .WithMany();

And finally I made helper methods BeFriend and BecomeTeacherStudent, which make sure that when you become friend with someone he becomes friend with you (and the respective thing for teacher-student).

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