title: How to determine number of children of a record?
body: <p>Good afternoon everyone!</p>
  
  <p>I'm studying NHibernate, and decided to make some changes. Among them, I noticed that some fields are unnecessary. So I bring my doubt:
  I have a list, let's call it Class_List within each study class, I can have N students for each class. Within the list Class_List, I also have other properties as simple as the name of the class.
  How I see it is unnecessary to store how many students I have in the database, I would, in a single query, how many records I have. This, using NHibernate.</p>
  
  <p>Is this possible? How?</p>
  
  <p>Best regards,</p>
  
  <p>Gustavo.</p>
  
  <p>Edit: I've forgot to say one thing... I want to return this number of record, as a column. But this column is not mapped in my .hbm.xml file. </p>