title: Entity framework 4.1 - DbUpdateExcepetion when remove entity with include or load
body: <p>I'm trying to remove object from my context using the "remove" method.
  But i get an UpdateException saying :</p>
  
  <blockquote>
    <p>ORA-01407: cannot update ("NAMUR_TEST_ALERTE"."TX_HST_TRACE_DATA"."TRD_ID_INFO_TRACE") to NULL</p>
  </blockquote>
  
  <p>where TRD_ID_INFO_TRACE is my foreign key.</p>
  
  <p>Here is my query linq :</p>
  
  <pre><code>List&lt;Trace&gt; query = (from t in Repository.DataContext.Trace                                          
                                       .Include("Datas")
                                        select t).ToList&lt;Trace&gt;();
  </code></pre>
  
  <p>If i suppress  the include instruction. It works fine.</p>
  
  <p>But i can't because, the purpose of this is to retreive datas, store them using serialization and finally, delete them from database.</p>
  
  <p>How can i make the remove keeping my include ?</p>
  
  <p>thanks in advance !</p>