   unset($stmt0);    $stmt0 = $db->query('SELECT id, label FROM test ORDER BY id ASC');   }   // fetch only the first rows and let closeCursor() clean up   $row0 = $stmt0->fetch(PDO::FETCH_ASSOC);   $stmt0->closeCursor();    $stmt0 = $db->prepare('UPDATE test SET label = ? WHERE id = ?');   $stmt0->bindValue(0, "