WP_Query - filter by multiple meta values and order by other meta values

Question

I'm trying to query posts using WP_Query and meta_query parameters:

$args = array(
    'post_type' => 'produkty',
    'meta_query' => array(
            'relation' => 'AND',
            array(
                    'key' => 'produkt_aktywny',
                    'value' => '1',
                    'compare' => '='),
            array(
                    'key' => 'produkt_dostepnosc',
                    'value' => '1',
                    'compare' => '=')
            )
);

$query = new WP_Query( $args );

What should I add to order the results by two other meta keys ('produkt_kategoria' and 'produkt_cena')?

Answer 1

<h3>Doing request</h3>



    <?php
        $query = new WP_Query($args);
        unset($GLOBALS['wp_query']);
        $GLOBALS['wp_query'] = $query;
        ?>

<br />
<br />
<h3>Request done but without sorting, all we need from that request is difficult mysql query $query->request. Next lets get this,modificate and do again</h3>
Principle is simple: explode and add mysql string which is needed<br />

    <?php
//****************************************************************************************
    /* THIS IS REQUEST WHICH I WRITE BY HANDS TO ATCHIVE THAT I NEED. VERY USEFULL TO DO THIS BEFO PROGRAMMING!
     * 
     * SELECT wp_posts.ID FROM wp_posts 
     * INNER JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id) 
     * INNER JOIN wp_postmeta featured ON (wp_posts.ID = featured.post_id) 
     * WHERE 1=1 
     * AND wp_posts.post_type = 'car' 
     * AND (wp_posts.post_status = 'publish') 
     * AND ( (wp_postmeta.meta_key = 'car_year' 
     * AND CAST(wp_postmeta.meta_value AS SIGNED) BETWEEN '1900' AND '2013') ) //DO NOT LOOK AT THIS, EXAMPLE
     * AND ( (featured.meta_key = 'car_is_featured') ) 
     * GROUP BY wp_posts.ID 
     * ORDER BY featured.meta_value ASC, wp_posts.post_modified_gmt DESC LIMIT 0, 20 
     */
//step 1
    $request = str_replace("SQL_CALC_FOUND_ROWS", "", $query->request); //remove unnecessary code
//step 2 - explode to insert mysql code for featured cars
    $tmp_request_array1 = explode('WHERE 1=1', $request);
    $tmp_request_array1[0].=" INNER JOIN $wpdb->postmeta featured ON ($wpdb->posts.ID = featured.post_id) ";
    $request = $tmp_request_array1[0] . " WHERE 1=1 " . $tmp_request_array1[1]; //assemble request again
//step 3 - explode assembled request to order by meta values
    $tmp_request_array1 = explode('ORDER BY', $request);
    $tmp_request_array2 = explode($order, $tmp_request_array1[1]);
    if ($orderby == 'post_modified_gmt') {
        $request = $tmp_request_array1[0] . ' ORDER BY ' . "featured.meta_value DESC, $wpdb->posts.post_modified_gmt $order" . $tmp_request_array2[1];
    } else {
        $request = $tmp_request_array1[0] . ' ORDER BY ' . "featured.meta_value DESC, $wpdb->postmeta.meta_value $order" . $tmp_request_array2[1];
    }
//step 4 - explode assembled request again to say that featured.meta_key is  =  'car_is_featured'
    $tmp_request_array1 = explode('GROUP BY', $request);
    $request = $tmp_request_array1[0] . " AND ( (featured.meta_key = 'car_is_featured') ) " . " GROUP BY " . $tmp_request_array1[1];
//**********************************************************
//step 5 - DO OUR NEW MYSQL REQUEST, AND GET CARS ORDER WE NEED
    $request_result = array();
    $tmp = $wpdb->get_results($request, ARRAY_N);
    foreach ($tmp as $value) {
        $request_result[] = $value[0];
    }
//***

    ?>

<br />
<br />

Full article read here