title: How can I link three different admin-users to an article?
body: <p>In my CMS/CRM-system, the <code>Article</code>-class has three <code>AdminUser</code> properties, one for "created by", one for "edited by" and one for "published by":</p>
  
  <pre><code>public class Article
  {
      public int Id { get; set; }
      // some more properties ...
      public AdminUser CreatedBy { get; set; }
      public AdminUser EditedBy { get; set; }
      public AdminUser PublishedBy { get; set; }
  }
  </code></pre>
  
  <p>The <code>AdminUser</code>-class:</p>
  
  <pre><code>public class AdminUser
  {
      public int Id { get; set; }
      public int MemberId { get; set; }
      // some more properties ...
      public Member Member { get; set; }
  }
  </code></pre>
  
  <p>(The <code>Member</code>-class just contains personal info like name, etc. In my system, not all members are admins, but all admins are members.)</p>
  
  <p>This works fine when I don't have any reference to <code>Article</code> in the <code>AdminUser</code>-class. But if I want to be able to know anything about the articles an admin has created, edited or published, they have to be a part of the <code>AdminUser</code>-class:</p>
  
  <pre><code>public class AdminUser
  {
      public int Id { get; set; }
      // ... and the rest of the properties
      public List&lt;Article&gt; CreatedArticles { get; set; }
      public List&lt;Article&gt; EditedArticles { get; set; }
      public List&lt;Article&gt; PublishedArticles { get; set; }
  }
  </code></pre>
  
  <p>Now, when trying to <code>add-migration</code>, I'm presented with the following error message:</p>
  
  <blockquote>
    <p>Unable to determine the relationship represented by navigation property 'AdminUser.Articles' of type 'List'. Either manually configure the relationship, or ignore this property using the '[NotMapped]' attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.</p>
  </blockquote>
  
  <p>I kind of understand what's going on, but I don't know how to "manually configure the relationship".</p>