title: EF Codefirst Convert Base Class to Derived Class
body: <p>Supposing the following entities :</p>
  
  <pre><code>public class Kisi
  {
      [Key]
      public int KisiID { get; set; }
      public string Ad { get; set; }
      public string Soyad { get; set; }
  
      public virtual ICollection&lt;Grup&gt; Gruplar { get; set; }
      public virtual ICollection&lt;Kampanya&gt; Kampanyalar { get; set; }
  }
  
  public class Musteri : Kisi
  {
      public int? Yas { get; set; }
      public string Meslek { get; set; }
  
  }
  </code></pre>
  
  <p>These two classes storing one table(TPH) in SQL SERVER. </p>
  
  <p>I saved a Kisi and this could be in relation to other tables.
  How can I cast/convert/"promote" it to a Musteri, keeping the same ID ? I can't recreate.</p>
  
  <p>I could issue a "manual" SQL INSERT, but it's kind of ugly...</p>
  
  <p>How can i handle it without loosing the KisiID ?</p>