function hook_views_data() {

  $data['users'] = array(
    'downloads' => array(
      'title' => t('Downloads'),
      'field' => array(
        'handler' => 'views_handler_field_numeric',
        'click sortable' => TRUE,
      ),
      'filter' => array(
        'handler' => 'views_handler_filter_numeric',
      ),
      'sort' => array(
        'handler' => 'views_handler_sort',
      ),
    ),
    'listens' => array(
      'title' => t('Listens'),
      'field' => array(
        'handler' => 'views_handler_field_numeric',
        'click sortable' => TRUE,
      ),
      'filter' => array(
        'handler' => 'views_handler_filter_numeric',
      ),
      'sort' => array(
        'handler' => 'views_handler_sort',
      ),
    )
  ),
);

function mta_views_query_alter(&$view, &$query) {

  foreach ($query->fields as $field_key => &$field_values) {
    if ($field_values['table'] == 'users') {

      switch ($field_values['field']) {
        case 'downloads':
          unset($query->fields[$field_key]);
          $query->add_field(null, "(SELECT COUNT(*) FROM {fileusage} fu WHERE fu.externaluser = {users}.uid AND fu.action = 0)", $field_key);
          break;
        case 'listens':
          unset($query->fields[$field_key]);
          $query->add_field(null, "(SELECT COUNT(*) FROM {fileusage} fu WHERE fu.externaluser = {users}.uid AND fu.action = 1)", $field_key);
          break;
      }
    }
  }
}