title: C# Entity Framework polymorphy in List
body: <p>I´ve got a Class Card, where every Card can have a List of <code>BlockMessages</code> and <code>BlockMessage</code> is <code>abstract</code> and implemented by different BlockMessages which should be saved as TPT. So far I´ve got this:</p>
  <pre><code>modelBuilder.Entity&lt;DbBlockApplication&gt;(app =&gt;
  {
     app.HasOne(x =&gt; x.Card as DbCard).WithMany(x =&gt; x.BlockMessages as List&lt;DbBlockApplication&gt;); // &lt;-- This line isn´t working
     anfa.ToTable(nameof(DbBlockApplication);
  
     modelBuilder.Entity&lt;DbFreeBlock&gt;(app =&gt;
     {
        app.HasOne(x =&gt; x.Card as DbCard).WithMany(x =&gt; x.BlockMessages as List&lt;DbFreeBlock&gt;); // &lt;-- This line isn´t working
        anfa.ToTable(nameof(DbFreeBlock);
     });
  }
  </code></pre>
  <p>Card has the following Property:</p>
  <pre><code>public interface IDbCard : IDbEntity
  { 
      List&lt;IDbBlockMessage&gt; BlockMessages { get; set; }
  }
  </code></pre>
  <p>Now I want to archive that every BlockMessage has a Foreign-Key on Card and on Load the Card loads all BlockMessages into the field BlockMessages. Perfectly would be when the BlockMessages gonna load by Time Order.</p>