Sort Posts By Custom Field Date?

According to the query_posts() article, you would need to use something like:

query_posts('cat=3,4,5,6&order=desc&orderby=meta_value&meta_key=event_date');

Assuming you order=desc is still okay.

Note that your Custom Field would need dates entered in a format such as “20091022” (for Oct 22, 2009) for the sorting to work.

I’ve never tried the combination of category and custom value that MichaelH suggested. I’ve found the query posts parameters work correctly when used by themselves, but my experience in combining them has been mixed. Some work some don’t.

I’d be inclined to use custom SQL on this which is why I linked you to the codex page.

I put this together for your situation

$querystr = "
    SELECT p.*
    FROM $wpdb->posts p, $wpdb->postmeta pm,
         $wpdb->term_relationships tr, $wpdb->terms t,
         $wpdb->term_taxonomy tt
    WHERE p.ID = pm.post_id
      AND p.post_type = 'post'
      AND pm.meta_key = 'date'
      AND p.ID = tr.object_id
      AND tr.object_id = tt.term_taxonomy_id
      AND tt.term_id = t.term_id
      AND t.term_id in (3, 4, 5)
    ORDER BY pm.meta_value DESC
    ";

Won’t guarantee its 100% correct but it ran in MySQL

See this section for the code you need to run this query. Substitute the query code above for the query code in the section I linked to. You can work the example code on the codes page into your existing loop. The comments there about OBJECT being required, and the need to include setup_postdata() are true.

my solution is 2 loop, the first

$agenda = get_posts('category=4&numberposts=10');
	<?php
// an empty array
$date_order = '';
if( $agenda ) : ?> <?php  foreach( $agenda as $post ) : setup_postdata( $post ); ?> 

<?php 	$custom_date = get_post_custom_values('custom_date');
	if (isset($custom_date[0])) {
	$evento = strtotime($custom_date[0]);
	} else {
   $evento = strtotime($post->post_date_gmt);
			}
	$date_order[$evento] = $post->ID;

// now the array contain key as date and post ID as value
	 ?>

	<?php endforeach;  ?>
 	<?php endif; ?>

// and the second

// order the date in the custom field
ksort($date_order);

foreach ($date_order as $key => $val) {
 query_posts('p='.$val);
global $more;
$more = 0; 

// the second Loop
while (have_posts()) : the_post(); ?>
// your stuff here
	<?php endwhile; ?>
 <?php	} ?>

in this way i can order post with or without date custom field
there are too many query?
it’s too many expensive?