Order by custom date field

Question

This one has been bugging me for a while. I've used Verve Meta Boxes plugin to add a date field to a custom post type I created, and I would like to somehow order by this field when using query_posts in PHP. What's the best way to do this? I haven't been able to figure out a way that didn't involve complicated custom queries.

Answer 1

I found the following solution:

SELECT wposts . *
            FROM $wpdb->posts wposts, $wpdb->postmeta wpostmeta
            WHERE wposts.ID = wpostmeta.post_id
            AND wpostmeta.meta_key =  'datum'
            AND wposts.post_type =  'optredens'
            AND wposts.post_status =  'publish'
            ORDER BY wpostmeta.meta_value ASC 

As other query_posts() methods / alternatives did not work very well.

Answer 2

It would help to see all of your code, without more context it's just shots in the dark. I use this to accomplish what you're trying to do, using date format YYYY-MM-DD and it absolutely ‘works for me’.

global $wp_query;
$args = array(
    'meta_key' => 'datum',
    'orderby' => 'meta_value_num',
    'order' => 'ASC'
);
$args = array_merge( $wp_query->query, $args );
query_posts( $args );