title: creating a join alias - how to?
body: <p>I'm wanting to do something like</p>
  
  <pre><code>SELECT
      t.subtitle
  FROM
      temp t
      LEFT JOIN ep e ON e.subtitle=t.subtitle AND e.episode=t.episode AS se
  WHERE se IS NULL
  GROUP BY t.subtitle, t.episode;
  </code></pre>
  
  <p>So that the where clause can refer to the result of the left join, is this possible or do I have to use a different method? (episode and subtitle are indexed in both tables)</p>
  
  <p>Thanks,
  Paul</p>
  
  <p><strong>UPDATE</strong>  When I say result I mean the left table returns no matches for e.subtitle=t.subtitle and e.episode=t.episode</p>
  
  <p>Do I have to instead do</p>
  
  <pre><code>SELECT
      t.subtitle
  FROM
      temp t
      LEFT JOIN ep e ON e.subtitle=t.subtitle AND e.episode=t.episode
  WHERE e.subtitle IS NULL AND e.episode IS NULL
  GROUP BY t.subtitle, t.episode;
  </code></pre>