title: ADO.NET Entity Framework: Update Wizard will not add tables
body: <p>I <a href="https://i.stack.imgur.com/5CduL.png" rel="nofollow noreferrer">added a new ADO.Net Entity Data Model</a> into my project and used the <a href="https://i.stack.imgur.com/c4Pju.png" rel="nofollow noreferrer">Update Wizard</a> to add tables into the model.  Five of the selected tables were added to the design surface.  Two other tables will not add.  I select them in the wizard and click Finish, yet they never show up on the design surface.</p>
  
  <p>Is this a bug, or are there some situations where a table cannot be added to the model (by design)?</p>
  
  <hr />
  
  <p>UPDATE: The XML (*.edmx) reveals the problem.  </p>
  
  <pre><code>&lt;!--Errors Found During Generation:
  warning 6013: The table/view 'FooBar.dbo.Roles' does not 
  have a primary key defined and no valid primary key could be inferred. 
  This table/view has been excluded. To use the entity you will need to 
  review your schema, add the correct keys and uncomment it.--&gt;
  &lt;!--&lt;EntityType Name="Roles"&gt;
      &lt;Property Name="role_id" Type="decimal" /&gt;
      &lt;Property Name="role_desc" Type="nvarchar" MaxLength="30" /&gt;
  &lt;/EntityType&gt;--&gt;
  </code></pre>