title: BaseEntity in Entity Framework Model First
body: <p>I have a small problem with EF Model First. I wanna have one generic entity not mapped to any database table. Entity with only one property Int Id. And all other entities should derive from this one. (Thanks to that base class i will be able to make very generic repository).</p>
  
  <p>I already have all my entities except that base (till now each of them had their own key property).</p>
  
  <p>When i try to Add my BaseEntity i get error:</p>
  
  <pre><code>Problem in mapping fragments starting at line 614:Must specify mapping for all key properties (BaseEntities.Id) of the EntitySet BaseEntities.
  ...\DataAccess\Model.edmx
  </code></pre>
  
  <p>No matter if BaseEntity is set to abstract or not.</p>
  
  <p>The same errors appears again with any other Entity that derives from that one.
  In Code First this would be very simple but i have no idea how to do it in a good way with Model First.</p>
  
  <p>What am I doing wrong?</p>