如何在ASP.Net MVC 5中处理多个表(用户)-Fluent API [英] How to handle many to many same table (User) in ASP.Net MVC 5 - Fluent API

问题描述

我正在学习ASP.Net MVC 5，并且坚持使用一种基本的DB设计. 所以，我有一个用户，可以推荐很多人在工作 此外，许多人都可以申请获得推荐.我已经创建了两个角色，所有这些都已得到照顾.现在，我在名为 Referral 的课程上，它将跟踪需要完成的每个Referral实例.

I am learning ASP.Net MVC 5 and I am stuck with one basic DB Design. So, I have one User which can refer many person in job Also, many person can apply to get themselves Referred. I have created two roles and all of that is taken care. Now, I have on class called Referral which will keep track of every instance of Referral that needs to be done.

引荐模型:

Public class Referral
{
     [Key]
        public int ReferralId { get; set; }
        public Company Company { get; set; }
        public int CompanyId { get; set; }
        public ApplicationUser User { get; set; }
        public string CandidateId { get; set; } // Application User ID of person asking for referral
        public string ReferrerId { get; set; } // Application user ID of person referring the candidate
}

ApplicationUser模型

ApplicationUser Model

  public class ApplicationUser : IdentityUser
    {
        public ICollection<Referral> Referrals { get; set; }
        // rest prop removed for brevity sake
    }

现在，假设A(推荐人)引用B(候选人).我的表格行将如下所示.

Now, suppose A(Referrer) refers B(Candidate). My Table row will look like below.

ReferralId     CompanyId     CandidateId   ReferrerId

1              1             B             A

那么好.但是我想在推荐表上建立FK关系.我是Fluent API的新手，但我尝试如下进行操作.

So, far so good. But I want to establish FK relationship on Referral table. I am new to Fluent API but I tried like below.

    // one candidate can have many referrals
    dBModelBuilder.Entity<ApplicationUser>()
    .HasMany(u => u.Referrals)
    .WithRequired(u => u.User)
    .HasForeignKey(u => u.CandidateId)
    .WillCascadeOnDelete(false);

    //one referrar can have many referrals
    dBModelBuilder.Entity<ApplicationUser>()
    .HasMany(u => u.Referrals)
    .WithRequired(u => u.User)
    .HasForeignKey(u => u.ReferrerId);

但是EF只尊重一种关系.为什么两个外键关系都没有设置.如果我注释掉一个，那么其他作品，反之亦然.但是，如图所示将它们放在一起永远不会起作用.

But EF respects only one relationship. Why both the foreign key relationhip is not getting set. If I comment out one then other works, and vice versa. But keeping them together as shown never works.

预期的行为:我希望有两个FK关系.一旦有了这些，我就可以相应地工作.请在这里指导我.我是这一切的新手.

Expected Behaviour: I expected to have two FK relationship. Once I have that then I can work accordingly. Please guide me here. I am new to all this.

推荐答案

正如评论中提到的@SLaks一样，要具有两个关系，您需要两个导航属性(每个FK一个).

As @SLaks mentioned in the comments, in order to have two relationships, you need two havigation properties (one for each FK).

因此，在 one 端，将Referrals属性替换为以下内容:

So in the one side replace Referrals property with something like this:

public class ApplicationUser : IdentityUser
{
    // ...
    public ICollection<Referral> ReferrerOf { get; set; }
    public ICollection<Referral> CandidateOf { get; set; }
}

在许多端将User属性替换为:

at many side replace the User property with:

public class Referral
{
    // ...
    public ApplicationUser Candidate { get; set; }
    public ApplicationUser Referrer { get; set; }
}

并将它们与流利的API相关联:

and correlate them with fluent API:

modelBuilder.Entity<ApplicationUser>()
    .HasMany(u => u.CandidateOf) // <--
    .WithRequired(r => r.Candidate) // <--
    .HasForeignKey(r => r.CandidateId)
    .WillCascadeOnDelete(false);

modelBuilder.Entity<ApplicationUser>()
    .HasMany(u => u.ReferrerOf) // <--
    .WithRequired(r => r.Referrer) // <--
    .HasForeignKey(r => r.ReferrerId);

只要正确地关联了导航属性的名称，它们实际上就无关紧要.

The names of the navigation properties don't really matter as soon as you correlate them correctly.

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