title: ZF2 + Zend\Db\Sql\Insert + ON DUPLICATE KEY UPDATE
body: <p>I would like to insert some data using Zend\Db\Sql\Insert with the option <strong>ON DUPLICATE KEY UPDATE</strong></p>
  
  <p>Actually I use this kind of query:</p>
  
  <pre><code>INSERT INTO `user_data` (`user_id`, `category`, `value`) 
  VALUES (12, 'cat2', 'my category value')
   ON DUPLICATE KEY UPDATE `user_id`=VALUES(`user_id`), `category`=VALUES(`category`), `value`=VALUES(`value`);
  </code></pre>
  
  <p>with</p>
  
  <pre><code>$this-&gt;dbAdapter-&gt;query($sql, Adapter::QUERY_MODE_EXECUTE);
  </code></pre>
  
  <p>But how I can generate this above query with <strong>Zend\Db\Sql\Insert</strong> ?</p>
  
  <p>thanks for any suggestion.
  Cheers</p>