Check what nodequeues are used in views

example.php

<?php

/**
 * Check what nodequeues are used in views
 * 
 * Usage:
 *   drush ev "luxian_nodequeue_stats();"
 */
function luxian_nodequeue_stats() {
  if (!drupal_is_cli()) {
    return;
  }
  
  $nodequeues = db_select('nodequeue_queue', 'nq')
    ->fields('nq', array('name', 'title'))
    ->execute()
    ->fetchAllAssoc('name');

  
  $q = db_select('views_view', 'vv');
  $q->fields('vv', array('vid', 'name', 'human_name'));
 
  $q->leftJoin('views_display', 'vd', 'vd.vid = vv.vid');
  $q->fields('vd', array('id', 'display_title', 'display_options'));
  $q->addExpression("CONCAT(vv.name, ':', vd.id)", 'display_full_id');
  
  $results = $q->execute()->fetchAllAssoc('display_full_id');
  foreach($results as $key => $result) {
    $result->display_options = unserialize($result->display_options);
    
    if (isset($result->display_options['relationships']['nodequeue_rel'])) {
      $relationship = $result->display_options['relationships']['nodequeue_rel'];
      
      foreach($relationship['names'] as $key => $value) {
        if (!empty($value) && $key == $value && isset($nodequeues[$key])) {
          $nodequeues[$key]->views[$result->name]['human_name'] = $result->human_name;
          $nodequeues[$key]->views[$result->name]['displays'][$result->id] = $result->display_title;
        }
      }
    }
  }
  
  $indentation = "\t"; 
  foreach($nodequeues as $nq) {
    echo "{$nq->title} ({$nq->name})\n";
    
    if (empty($nq->views)) {
      echo $indentation . "Not used in any view\n";
    }
    else {
      foreach($nq->views as $view_id => $view) {
        echo $indentation . "{$view['human_name']} ($view_id):\n";
        foreach($view['displays'] as $display_id => $human_name) {
          echo $indentation . $indentation . "$human_name ($display_id)\n";
        }
      }
    }
  }
}