title: Are there any arithmetic operation projections in NHibernate?
body: <p>I would like to get this SQL from NHibernate: </p>
  
  <pre><code>SELECT SUM(color_pages) * SUM(total_pages)
  FROM connector_log_entry
  GROUP BY department_name
  </code></pre>
  
  <p>But I can't find any arithmetic operation (*) projections anywhere.</p>
  
  <p>This is the code that I have so far:</p>
  
  <pre><code>Session.QueryOver&lt;ConnectorLogEntry&gt;()
         .SelectList(list =&gt; list
             .SelectGroup(m =&gt; m.DepartmentName)
             .WithAlias(() =&gt; dto.Department)
             .Select(Projections.Sum&lt;ConnectorLogEntry&gt;(m =&gt; m.TotalPages))
             //.Select(Projections.Sum&lt;ConnectorLogEntry&gt;(m =&gt; m.ColorPages))
             .WithAlias(() =&gt; dto.TotalColorPercentage))
         .TransformUsing(Transformers.AliasToBean&lt;DepartmentConsumption&gt;());
  </code></pre>