title: How to update only modified values (EntityFramework 5.0)?
body: <p>I have this entity, want to update using entityframework</p>
  
  <pre><code> EmployeeModel employee = new EmployeeModel
      {
          Id = 1000, //This one must 
          FirstName = modifiedValue,
          Email = modifiedValue, 
          LastName = originalValue,
          Phone = originalValue
      };
  </code></pre>
  
  <p>Code to update</p>
  
  <pre><code>_db.ObjectStateManager.ChangeObjectState(employee, EntityState.Modified);  
  _db.SaveChanges();
  </code></pre>
  
  <p>This is the SQL statement got once updated </p>
  
  <pre><code>Update Employee set Id=1138,FirstName='modifiedValue',Email='modifiedValue',LastName= 'OriginalValue',phone='originalValue' where Id=1138
  </code></pre>
  
  <p>But I am expecting this</p>
  
  <pre><code>Update Employee set FirstName='modifiedValue', Email='modifiedValue' where Id=1138.
  </code></pre>
  
  <p>I dont know what I am missing here. Please let me know. </p>