title: InvalidOperationException: The property is part of the object's key information and cannot be modified
body: <p>I'm getting this error when I try to change column value.</p>
  
  <p>Here is how I got to this problem:</p>
  
  <p>1) I was needed to add this bit column to an Existing table.</p>
  
  <pre><code>    ALTER TABLE BooksDB.dbo.Books
      ADD edited bit NOT NULL DEFAULT(0),
  </code></pre>
  
  <p>2) Updated my EF model in project.</p>
  
  <p>3) Now when I try to change 'edited' property of entity object, I'm getting the error from Subject line.</p>
  
  <p>Why is that?</p>
  
  <p>EF object declaration:</p>
  
  <pre><code>    /// &lt;summary&gt;
      /// No Metadata Documentation available.
      /// &lt;/summary&gt;
      [EdmScalarPropertyAttribute(EntityKeyProperty=true, IsNullable=false)]
      [DataMemberAttribute()]
      public global::System.Boolean edited
      {
          get
          {
              return _edited;
          }
          set
          {
              if (_edited != value)
              {
                  OneditedChanging(value);
                  ReportPropertyChanging("edited");
                  _edited = StructuralObject.SetValidValue(value);
                  ReportPropertyChanged("edited");
                  OneditedChanged();
              }
          }
      }
      private global::System.Boolean _edited;
      partial void OneditedChanging(global::System.Boolean value);
      partial void OneditedChanged();
  </code></pre>