title: Fetching only base type objects in nHibernate
body: <p>I'm currently trying to solve a problem. I have a class table inheritance aka table-er-subclass (one main table + several others with additional data). In my app both base object instances and extended objects can exist. Now I want to be able to sometimes fetch only those base objects and sometimes both types. A simple example (both classes are mapped with all of their properties) </p>
  
  <pre><code>public class Base 
  {
    public in ID {get; set;}
    public string Something {get; set;}
  }
  
  public class Extended : Base 
  {
    public bool NewProp{get; set;}
  }
  </code></pre>
  
  <p>now running hql query "from Base" would fetch both Base and Extedned objects. Is there any way to restrict such behavior to fetch only Base objects?</p>