Question

I’m ordering my posts by a custom meta value named “size”.

$querystr = "
    SELECT $wpdb->posts.* 
    FROM $wpdb->posts, $wpdb->postmeta
    WHERE $wpdb->posts.ID = $wpdb->postmeta.post_id 
    AND $wpdb->postmeta.meta_key = 'size'
    AND $wpdb->posts.post_status = 'publish' 
    AND $wpdb->posts.post_type = 'post'
    AND $wpdb->posts.post_date < NOW()
    ORDER BY $wpdb->postmeta.meta_value DESC
 ";

 $pageposts = $wpdb->get_results($querystr, OBJECT);

if ($pageposts):
  global $post; 
  foreach ($pageposts as $post):      
  setup_postdata($post);     
      the_title();      
  endforeach;    
endif; 

wp_pagenavi(); //creates page navigation

At the same time I’m using the WP-pagenavi plugin to navigate the posts by pages. I have 10 posts on each page.

The problem: Posts are ordered separately in each page. How can I order posts in descending order through all pages?

Update: I might have found a solution but I’m not sure how to implement it in my code

http://scribu.net/wordpress/wp-pagenavi/wpn-2-74.html

$my_query = new WP_Query( array( 'tag' => 'foo', 'paged' => get_query_var('paged') ) );

while ( $my_query->have_posts() ) : $my_query->the_post();
    the_title();
    // more stuff here
endwhile;

wp_pagenavi( array( 'query' => $my_query ) );

wp_reset_postdata();    // avoid errors further down the page

Answer 1

I’ve found a SO post that can solve your problem :

How to sort a 'query_posts' function by custom field, while limiting posts by another custom field

There you will find a custom class extending WP_Query and allowing you to make a query ordered by a custom field, and to include the paged query var too.

So the steps :

1. Past the class PostsOrderedByMetaQuery code somewhere like in your functions.php

2. Replace your query by :

   // Retrieve `paged` in URL
   $paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
   
   // Make the query like in WP_Query but with our custom class
   $query = new PostsOrderedByMetaQuery(array(
     'post_type'   => 'post',
     'post_status' => 'publish',
     'paged'       => $paged,
     'orderby_meta_key' => 'size',
     'orderby_order'    => 'DESC'        
   ));
   

3. Use it !

   while ( $query->have_posts() ) : $query->the_post();
       the_title();
       // more stuff here
   endwhile;
   
   wp_pagenavi( array( 'query' => $query ) );
   
   wp_reset_postdata();    // avoid errors further down the page