How to only display posts whose meta_value field is not empty?

Three people have already tried to solve this, and we’re coming up nil. I want to show only posts that have a value in the meta_key ‘featured_image’.

So… if ‘featured_image’ is not empty, show the post. Here’s the code:

      <ul>
      <?php
      $args = array(
        'showposts' => 5,
        'meta_query' => array(
          array(
            'key' => 'featured_image',
            'value' => '',
            'compare' => '!='
            )
          )
      );
      $ft_pagination = new WP_Query( $args );
      ?>
      <?php while ($ft_pagination->have_posts()) : $ft_pagination->the_post(); ?>
        <?php $ftimage = get_post_meta(get_the_id(), 'featured_image', TRUE); ?>
        <li>
          <article>
            <a href="">
            <?php if ($ftimage): ?>
              <img src="<?php bloginfo('template_directory'); ?>/timthumb.php?src=<?php echo $ftimage; ?>&w=84&h=60" alt="" />
            <?php else: ?>
              <img src="<?php bloginfo('template_directory'); ?>/timthumb.php?src=/wp-content/themes/ssv/images/review-default.gif&w=84&h=60" alt="" />
            <?php endif; ?>
            </a>
          </article>
        </li>
      <?php
      endwhile;

      wp_reset_query();
      ?>
      </ul>

We have tried literally every combination we can think of, the deprecated meta_* options, query_posts, get_posts, instead of WP_Query… Nothing. Printed the select statement, no meta value field is showing. It exists – for the posts (for every post) and it exists in the db.

We’ve seen every post out there on the topic right now, including these:

query_posts and only show results if a custom field is not empty

http://scribu.net/wordpress/advanced-metadata-queries.html

Zilch. Please help…

Hi @Rob:

The reason you can’t figure out how to do it is because it’s not possible, at least not without resorting to SQL. Try adding the following to your theme’s functions.php file:

add_filter('posts_where','yoursite_posts_where',10,2);
function yoursite_posts_where($where,$query) {
  global $wpdb;
  $new_where = " TRIM(IFNULL({$wpdb->postmeta}.meta_value,''))<>'' ";
  if (empty($where))
    $where = $new_where;
  else
    $where = "{$where} AND {$new_where}";
  return $where;
}

If you have custom 'featured_image' fields with empty values the above will filter them out. If you problem is something else, we’ll have to see what your data looks like to solve it.

One thing I’m curious about; how did you get empty values for 'featured_image'? The admin UI in WordPress 3.1 does its best to keep you from entering empty values.
Hope this helps.