title: SELECT max one value per day (stored in unix timestamp)
body: <p>I've a MySQL table that has various values per user and per day, but the created is an INT with unix timestamp:</p>
  
  <pre><code>id INT, AUTO_INCREMENT
  users_id INT
  value INT
  created INT
  </code></pre>
  
  <p>I need to select maximum one value per day and per user, for the last 30 days. If it was a MySQL TIMESTAMP I would do something like: <code>SELECT * FROM table GROUP BY DAY(created)</code> but I can't do it with a UNIX timestamp.</p>
  
  <p>Any idea on how I can reproduce a similar query with the current data?</p>