Multiple Queries in one loop (custom fields)

Hello,

I have, on my category.php page, some filters to sort out results.
In this example, I want to sort “Expositions” by these terms : ‘date’, ‘zip_code’,’subcategory’.

I made links like this :

<a href="<?php echo add_query_arg(array('date' => 'now')); ?>">Now</a>, so I have this URL : …/expositions/?date=now

To sort out by ‘date’, I use this arguments for my custom query :

$date_args = array('meta_query' => array(
'relation'=>'AND',
array(
 'key' => 'date_start',
 'value' => date('Y m d'),
 'compare' => '<=',
 'type' => 'CHAR'),
array(
 'key' => 'date_end',
 'value' => date('Y m d'),
 'compare' => '>=',
 'type' => 'CHAR'
)));

Then I merge my args :

$args = array_merge( $wp_query->query, $date_args );
query_posts($args);

This works fine, but I’m trying to “mix” terms to sort results, I get into trouble…

To sort out by ‘zone’, I use this arguments for my custom query :

$zone_args = array('meta_query' => array(
array(
'key' => 'code_postal',
'value' => $listeZones['paris_c'],
'compare' => 'IN',
'type' => 'numeric'
))
);

I’m looking for a solution to mix both custom queries. Because if my URL parameters are “?date=now&zone=paris_center”, I want ONLY posts that match both criterias.

I don’t know if I’m clear…sorry for my bad english.

Thanks for help ! 🙂