title: SQL LEFT OUTER JOIN subquery
body: <p>I have SQL data that looks like this:</p>
  <pre><code>events
  id name         capacity
  1  Cooking        10
  2  Swimming       20
  3  Archery        15
  
  registrants
  id  name
  1   Jimmy
  2   Billy
  3   Sally
  
  registrant_event
  registrant_id  event_id
       1             3
       2             3
       3             2
  </code></pre>
  <p>I would like to select all of the fields in 'events' as well as an additional field that is the number of people who are currently registered for that event.  In this case Archery would have 2 registrants, Swimming would have 1, and Cooking would have 0.</p>
  <p>I imagine this could be accomplished in a single query but I'm not sure of the correct syntax. <strong>How would a query be written to get that data?</strong></p>