Error when WP_Query parses orderby array in function parse_order

[oloynet]

Example of request where I want to order by two custom fields in meta query
start_date_order and is_sticky

$args = array(
    'no_found_rows'  => true ,
    'posts_per_page' => 4,
    'post_type'      => 'event',
    'post_status'    => 'publish',

    'meta_query' => array(
        'relation' => 'AND',
        array(
            'key'  => 'start_date_order',
            'type' => 'UNSIGNED',
        ),
        array(
            'key'  => 'is_sticky',
            'type' => 'UNSIGNED',
        ),
    ),
    'orderby' => array(
        'start_date_order' => 'DESC',
        'is_sticky'        => 'ASC',
    ),
);

The '$primary_meta_query' var in method parse_order( $order ) is set forever with the first item of '$meta_clauses' array

see line 2336 /wp-includes/query.php

<?php
$primary_meta_query = reset( $meta_clauses );

I fix the problem with the following PHP code

<?php
//$primary_meta_query = reset( $meta_clauses );

$primary_meta_query = array();
foreach( $meta_clauses as $meta_clause ) {

    if( $meta_clause['key'] == $orderby ) {
        $primary_meta_query = $meta_clause;
        break;
    }
}

Now the good sql query is look like :

SELECT wp_posts.ID
FROM wp_posts
INNER JOIN wp_postmeta ON ( wp_posts.ID = wp_postmeta.post_id )
INNER JOIN wp_postmeta AS mt1 ON ( wp_posts.ID = mt1.post_id )
WHERE 1=1
AND (
  wp_postmeta.meta_key = 'start_date_order'
  AND mt1.meta_key = 'is_sticky'
)
AND wp_posts.post_type = 'event'
AND ((wp_posts.post_status = 'publish'))
GROUP BY wp_posts.ID
ORDER BY CAST(wp_postmeta.meta_value AS UNSIGNED) DESC, CAST(mt1.meta_value AS UNSIGNED) ASC
LIMIT 0, 3

[ocean90]

Hello @oloynet,

this Trac is for WordPress.org. For the software WordPress we have ​https://core.trac.wordpress.org/.