Order custom post type by posts with most likes first

Question

I am using the Like/Dislike plugin on a custom post type and am trying to order the display of posts by the most like count down to those that have no likes (and no set meta value in the posts meta table).

My current query is the following:

$args = array(  
    'post_type' => 'idea',
    'post_status' => 'publish',
    'posts_per_page' => -1,
    'meta_key' => 'pld_like_count',
    'orderby' => 'meta_value_num title',
    'order' => 'DESC'
  );

This displays only the posts that have a defined meta_key and meta_value for the Like/Dislike plugin.

Is there a way to order posts from the most likes down to those without the defined meta_key/value?

Posts without a set like meta_key/value still need to be displayed because users need to be able to like the posts with the button.

Answer 1

Yes, there is — use a meta_query with 2 clauses, one which selects posts having the meta, and the second clause with a 'compare' => 'NOT EXISTS' which selects posts without that meta.

So in your $args array, just replace the 'meta_key' => 'pld_like_count' with this one:

'meta_query' => array(
    // make sure it's OR
    'relation' => 'OR',

    array( // selects posts having the meta
        'key'  => 'pld_like_count',
        'type' => 'NUMERIC',
    ),

    array( // selects posts without the meta
        'key'     => 'pld_like_count',
        'compare' => 'NOT EXISTS',
    ),
),