Order by option within a post object field

• djcottrell

• May 31, 2019 at 11:26 pm

I have a post type of listing. In each listing is post object named package that is connected to another post type of package. There is then a field attached to each package named sort. I need to be able to use the sort value to order the listings.

add_action('pre_get_posts','alter_query');
function alter_query($query) {
    global $wp_query;

    if( $query->is_main_query() && is_post_type_archive( 'listing' ) ) {

        // Package is a post object attached to the listing post type. 
        // It allows you to select from a packages post type.
        $package = get_field('package');

        // Sort is a numeric field attached to the packages post type.
        $sort = get_field('sort',$package->post_ID);

        $query->set('orderby', array( 
          ...
        ));

        remove_all_actions ( '__after_loop');
    }
}

• John Huebner

• June 3, 2019 at 12:32 am

You cannot sort posts by a meta value attached to a different post. You can only sort posts by meta fields attached to the post you are sorting. There simply is not a way to do this in WP.

posts you are sorting
    => meta values of these posts <= you can sort by these
    => Related post
       => meta values of related posts <= you cannot sort the first level posts by this