drupal basic sql query

Hi, Please could someone help

This is my call:

  
function zendcalender_data() {
  $query = db_select('node', 'n')
      ->fields('n', array('nid', 'title', 'created'))
      ->leftJoin('field_data_field_event_date', 'fed', "(fed.entity_id = n.nid AND fed.entity_type = node AND fed.deleted = 0)")
      ->condition('status', 1)
      ->orderBy('created', 'DESC'); 
  $query->execute();


  return $query;
}

In drush I'm just running a simple php script with print_r using the php-script command on the returned data and I'm getting this error.
...
Drush command terminated abnormally due to an unrecoverable error.                                             Error: Call to a member function condition() on a non-object in... line (the one with orderBy above)

Whats going on?

Thanks  Darren