Hide posts with meta key in WP_Query

Question

I was reading this post to "Exclude posts with specific meta_value" but it does not work correctly. Here is the arguments I am passing to WP_Query :

      $args=array(
        'cat' => $catid,
        'category__in'=> $term_ids,
        'post_type' => 'post',
        'post_status' => 'publish',
        'posts_per_page' => -1,
        'meta_query' => array(
            array(
                'key' => 'featured_post',
                'value' => 'on',
            ),
        ),
      );

Using the above method, I can list posts which use meta key, but I do not want posts, with meta key "featured_post" to be displayed. If I change the value to something else then no post is displayed.

The meta value is simply a check box for featured posts.

Answer 1

Use compare with NOT EXISTS to get posts without that meta key.

'meta_query' => array(
    array(
        'key'     => 'featured_post',
        'compare' => 'NOT EXISTS',
    ),
)