title: Zend framework $db->update result
body: <p><code>Zend_Db_Adapter::update()</code> returns the number of rows affected by the update operation.
  What is best way to determine if the query was successful?</p>
  
  <pre class="lang-php prettyprint-override"><code>$data = array(
      'updated_on'      =&gt; '2007-03-23',
      'bug_status'      =&gt; 'FIXED'
  ); 
  
  $n = $db-&gt;update('bugs', $data, 'bug_id = 2');
  </code></pre>