title: PDO update returns success, but doesn't update the database
body: <p>I'm using PDO to update a column in a table. It runs fine, and <code>execute()</code> returns <code>1</code> (success). But, when I check the database the value in the <code>status</code> column hasn't changed.</p>
  
  <pre><code>/*
   * Add jobs to the beanstalkd queue
   */
  foreach($jobs as $job) {
  
      $pheanstalk-&gt;useTube('scraper')-&gt;put(json_encode([
          'username' =&gt; $job['username'],
          'password' =&gt; $job['password'],
          'proxy'    =&gt; $job['proxy'],
          'gender'   =&gt; $job['gender'],
          'age'      =&gt; $job['age'],
          'device'   =&gt; $job['device']
      ]));
  
      /*
       * Update the row in the database and change its status to "queued"
       */
      try {
          $sql = "UPDATE cron_jobs SET status = :status WHERE id = :cid";
          $dbh-&gt;prepare($sql);
          $sth-&gt;bindValue(":status", "queued");
          $sth-&gt;bindValue(":cid", $job['cid']);
          print $sth-&gt;execute();
      } catch(PDOException $e) {
          syslog(LOG_ERR, $e-&gt;getTraceAsString());  
          exit;
      }    
  }
  </code></pre>
  
  <p>Any ideas? It's not reaching the <code>catch</code> block, and no exceptions occur.</p>