title: Persisting one table per class hierarchy using NHibernate without discriminator?
body: <p>I have an interface and a class which implements this interface. </p>
  
  <pre><code>public interface IPhase {
      string Description { get; set; }
      int Id { get; }
      string Phase { get; set; }
  }
  
  public class Phase : IPhase {
      // Implementation here...
  }
  </code></pre>
  
  <p>Now, using NHibernate 2.1.2.GA, I wish to use a table-per-class-hierarchy to map the interface and its implementor, and indeed, I don't need a discriminator, as this implementor will be the only class persisted in this table. I haven't used NHibernate for about a year and a half now, and I'm suffering some memory blanks here...</p>
  
  <p>I have read this question and answers which is related, except I'm not using FNH.<br>
  <a href="https://stackoverflow.com/questions/4470724/nhibernate-mapping-save-hierarchy-to-single-table-without-discriminator">NHibernate Mapping: Save hierarchy to single table without discriminator</a></p>
  
  <ol>
  <li><p>I wonder whether the <code>discriminator</code> attribute is obligatory while using <code>subclass</code>?</p></li>
  <li><p>What shall my XML mapping look like in this particular context?</p></li>
  </ol>
  
  <p>Thanks kindly for your help!</p>