title: nested sql queries in rails
body: <p>I have the following query</p>
  
  <pre><code>@initial_matches = Listing.find_by_sql(["SELECT * FROM listings WHERE industry = ?", current_user.industry])
  </code></pre>
  
  <p>Is there a way I can run another SQL query on the selection from the above query using a each do? I want to run geokit calculations to eliminate certain listings that are outside of a specified distance...</p>