title: NHibernate : Projection List
body: <p>I have the following code:</p>
  
  <pre><code>criteria.SetProjection(Projections.ProjectionList()
  .Add(Projections.Property("_personId")), "_ personId")
  .Add(Projections.Property("_firstName"), "_firstName")
  .Add(Projections.Property("_lastName"), "_lastName")
  .Add(Projections.Property("_address"), "_ address ")                
  .SetResultTransformer(Transformers.AliasToBean(typeof(Person)));
  </code></pre>
  
  <p>I get the following error:
  NHibernate.QueryException: property does not map to a single column: _address</p>
  
  <p>_address is a component of Person in Nhibernate Mapping.</p>
  
  <p>Is it possible to use Projections.Property on a component?</p>