What could be causing my wp_query pagination to break?

Question

I'm using categories and wp_query to create an "advanced search" feature on my website. It was working great until recently I noticed that the pagination was broken. The following 2 links should demonstrate the problem:

On page 1 I get 185 results:

http://www.barbadospropertylist.com/?cat%5Boffer%5D=24&cat%5Btype%5D=-1&cat%5Blocation%5D=-1&cat%5Bbedrooms%5D=-1&cat%5Bfurnishings%5D=-1&budget=1000000&cat%5Bparish%5D=-1&cat%5Bagent%5D=-1&cat%5Bbathrooms%5D=-1&submit=Advanced+Search

But on subsequent pages the query string breaks:

http://www.barbadospropertylist.com/page/2/?cat%5Boffer%5D=24&cat%5Btype%5D=-1&cat%5Blocation%5D=-1&cat%5Bbedrooms%5D=-1&cat%5Bfurnishings%5D=-1&cat%5Bparish%5D=-1&cat%5Bagent%5D=-1&cat%5Bbathrooms%5D=-1&budget=1000000&submit=Advanced+Search

You should see the second link redirect to:

http://www.barbadospropertylist.com/page/2/?budget=1000000&submit=Advanced%20Search

What with recent upgrades to WordPress I have no idea what might be causing this. Any pointers would be very, very welcome! I've been trying to figure this one out all day. :)

Here is my query code:

    query_posts(
    array_merge(
        wp_query->query,
        array(
            'category__and' => $pladvsearchcatids,
            'meta_key' => 'price',
            'orderby' => 'meta_value_num',
            'meta_compare' => '<=',
            'meta_value' => $plbudget,
            'order' => 'DESC'
        )
    )
);

Just noticed something really strange. When I download my site and work locally the problem goes away. The query string is not redirected on page 2 and paging through the results works as expected.

Answer 1

This might happen because you need to include the pagination information when you run custom queries with query_posts. Because custom query_post commands ignore any default values of the query_posts command. Here is an example of a query i have used to solve this problem in a simpler case (just to exclude a single category from the query):

   <?php
         if ( is_home() ) {
            $paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
            query_posts("cat=-19&paged=$paged");
         }
    ?>

Here is an example of how you can include this in your query. Don't know if this works for you, try it out and give me feedback. :)

    $paged = (get_query_var('paged')) ? get_query_var('paged') : 1;

    query_posts(
    array_merge(
        $wp_query->query,
        array(
            'category__and' => $pladvsearchcatids,
            'meta_key' => 'price',
            'orderby' => 'meta_value_num',
            'meta_compare' => '<=',
            'meta_value' => $plbudget,
            'order' => 'DESC',
            'paged' =>  $paged
        )
    )
);

Answer 2

Please try the following code:

$result = query_posts(
    wp_parse_args(
        $GLOBALS['wp_query']->query,
        array(
            'category__and' => $pladvsearchcatids,
            'meta_query' => array(
                array(
                    'key' => 'price',
                    'value' => $plbudget,
                    'compare' => '<='
                )
            ),
            'orderby' => 'meta_value_num',
            'order' => 'DESC',
            'paged' => get_query_var( 'paged' ) ? get_query_var( 'paged' ) : 1
        )
    )
);
// Check the output/query result:
echo '<pre>'; print_r( $result ); echo '</pre>';

Note, that your orberby value accepts only numeric values. You could try meta_value instead, if your output are (eventually) strings. In this case, the compare statement of <= won't work.