title: NHibernate custom SQL object creation
body: <p>Somewhat-simplified example situation: I have entities A and B which are incredibly "heavy" domain objects. Loading one from the database is a pretty big deal. Then I have an entity C, which is a very simple object that has a label string, one A, and one B -- both lazy.</p>
  
  <p>I'm doing some low-level querying to create huge lists of C, so I know exactly what IDs I need to save for C.A and C.B, but I <em>don't</em> want to load up entire objects and set them to the properties, because the overhead is insane.</p>
  
  <p>Instead, I want to just insert the IDs directly into my C entities, and then let the A and B properties on it be fully loaded later only if needed.</p>
  
  <p>I see the <code>&lt;sql-insert/&gt;</code> tag in the documentation, but the section is <em>really</em> sparse. </p>
  
  <p>Is there any way to do what I want to do inside the NHibernate framework, or should I just do raw SQL? I'm trying to keep database portability if possible, which makes me shy away from the raw option. Seems like there's got to be a better way I'm missing.</p>