title: GROUP BY does not remove duplicates
body: <p>I have a watchlist system that I've coded, in the overview of the users' watchlist, they would see a list of records, however the list shows duplicates when in the database it only shows the exact, correct number.</p>
  
  <p>I've tried <code>GROUP BY watch.watch_id</code>, <code>GROUP BY rec.record_id</code>, none of any types of group I've tried seems to remove duplicates. I'm not sure what I'm doing wrong.</p>
  
  <pre><code>SELECT watch.watch_date,
         rec.street_number,
         rec.street_name,
         rec.city,
         rec.state,
         rec.country,
         usr.username
  FROM
  (
      watchlist watch 
  
      LEFT OUTER JOIN records rec ON rec.record_id = watch.record_id
  
      LEFT OUTER JOIN members usr ON rec.user_id = usr.user_id
  )
  WHERE  watch.user_id = 1 
  GROUP BY watch.watch_id
  LIMIT 0, 25
  </code></pre>
  
  <p>The watchlist table looks like this:</p>
  
  <pre><code>+----------+---------+-----------+------------+
  | watch_id | user_id | record_id | watch_date |
  +----------+---------+-----------+------------+
  |       13 |       1 |        22 | 1314038274 |
  |       14 |       1 |        25 | 1314038995 |
  +----------+---------+-----------+------------+
  </code></pre>