title: EF Core 2 - Relationship with only 1 navigation property/relationship knowledge?
body: <p>I am using ASP.NET Core 2.2 with EF Core 2.2 and SQL server.</p>
  
  <p>I am currently working on a feature where I have the following classes:</p>
  
  <pre><code>TABLE Foo
  -------------------------------------------------------------
  Column                       Type          Remark
  --------------------------------------------------------------
  Id                           GUID          PK
  IntroId                      GUID?         Nullable FK
  IntroText                    Content       Navigation Property
  --------------------------------------------------------------
  
  TABLE Content
  --------------------------------------------------------------
  Column                       Type          Remark
  --------------------------------------------------------------
  Id                           GUID          PK
  Text                         string
  --------------------------------------------------------------
  </code></pre>
  
  <p>This is my fluent API configuration related to my issue: </p>
  
  <p><strong>Foo</strong></p>
  
  <pre><code>builder.HasOne(b =&gt; b.IntroText)
      .WithOne()
      .IsRequired(false);
  </code></pre>
  
  <p><strong>Content</strong><br>
  Content only has configuration for itself.</p>
  
  <p>Content can contain a lot of text and because of reasons, these things are not saved directly in the <code>Foo</code> table/class. </p>
  
  <p>As you can see, I am trying to make sure that <code>Content</code> does not have a foreign key/navigation property to <code>Foo</code>. This is because these properties are not part of <code>Content</code> and because in the future more classes/tables can have stuff like <em>IntroText</em>'s that are saved in the <code>Content</code> table and I dont want <code>Content</code> to be filled up with nullable foreign keys/navigation properties.</p>
  
  <h2>Is this possible with EF Core?</h2>
  
  <p>The error I get right now:</p>
  
  <p><em>The child/dependent side could not be determined for the one-to-one relationship between 'Foo.IntroText' and 'Content'. To identify the child/dependent side of the relationship, configure the foreign key property. If these navigations should not be part of the same relationship configure them without specifying the inverse. See <a href="http://go.microsoft.com/fwlink/?LinkId=724062" rel="nofollow noreferrer">http://go.microsoft.com/fwlink/?LinkId=724062</a> for more details.</em></p>
  
  <hr>
  
  <p>I would accept an answer that allows the database to have a relationship which I do not see in my codebase, but I would prefer that <code>Content</code> does not know anything about <code>Foo</code></p>
  
  <p>Thank you very much for your help!</p>