pager query with join

Question

I plan to list all polls in the most recent order where I need to join my "poll" table with the "node" table and display them with pager. Here is what I do:

$polls_query = db_select('poll', 'p')
              ->extend('PagerDefault')
              ->limit(3);
$polls_query->join('node', 'n', 'n.nid = p.nid')
            ->fields('p', array('nid'))
            ->condition('p.active', 1, '=')
            ->orderBy('n.created', 'DESC');
$result = $polls_query->execute();
foreach ($result AS $poll) {
  $polls[] = array('data' => drupal_render(node_view(node_load($poll->nid), 'teaser')));
}
$content['pager_list'] = array(
  '#theme' => 'item_list',
  '#items' => $polls,
  '#title' => t('Listing Consensus'),
  '#type' => 'ul',
);
$content['pager_pager'] = array('#theme' => 'pager');
return drupal_render($content);

Unfortunately I see a white screen of death and the php error log says "PHP Fatal error: Call to a member function fields() on a non-object in .. " and thats the line where I mention after fields. If I dont use join, everything works fine.

If anyone else has had similar problems, please share the solution.

Answer 1

The join() method doesn't return the query object to isn't chainable.

If you change your code to this you should be fine:

$polls_query = db_select('poll', 'p')
  ->extend('PagerDefault')
  ->limit(3);

$polls_query->join('node', 'n', 'n.nid = p.nid');

$polls_query->fields('p', array('nid'))
  ->condition('p.active', 1, '=')
  ->orderBy('n.created', 'DESC');

// etc...