title: 2nd MySQLi Query causes a "Call to a member function execute() on a non-object"
body: <p>I've got a strange problem. There are 2 queries. </p>
  
  <pre><code>$sql = "SELECT  `content_auftrag_id` 
          FROM `content` 
          WHERE `content_id` = '".$content_id."' LIMIT 1";
      $ergebnis = $db-&gt;prepare( $sql );
      $ergebnis-&gt;execute();
      $ergebnis-&gt;bind_result( $content_auftrag_vorhanden );
  
  $content_auftrag_id = "test";
  $sql = "UPDATE `content` SET `content_auftrag_id` = '".$content_auftrag_id."' 
          WHERE `content_id` = '".$content_id."'";
          $ergebnis2 = $db-&gt;prepare( $sql );
          $ergebnis2-&gt;execute();
  </code></pre>
  
  <p>When I use them both, then an error occurs for the second one. If I only run the the second, then it works fine. How can it be that both together cause an error?
  All variables are there and correct.</p>
  
  <p>Thanks!</p>