title: How to add results of two select commands in same query
body: <p>I currently have two select commands as per below. What I would like to do is to add the results together in the SQL query rather than the variables in code.</p>
  
  <pre><code>select sum(hours) from resource;
  select sum(hours) from projects-time;
  </code></pre>
  
  <p>Is it possible to have both in the same SQL and output a sum of both results?</p>