How to select WooCommerce products by post_meta and order them

Question

I'm using the following code to select products with the following post_meta keys: _product_new , _product_almost_new and _product_old .

My code:

add_action( 'woocommerce_product_query', 'custom_vtp_shop_order' );

function custom_vtp_shop_order($q){
    if ( ! $q->is_main_query() ) return;
    if (! is_admin() && (is_shop() || is_archive) ) {

        $q->set( 'tax_query', array(array(
            'taxonomy' => 'product_cat',
            'field' => 'slug',
            'terms' => array( 'Sold', 'Service' ),  
            'operator' => 'NOT IN'
        )));

        $q->set('meta_query', array(array(
            'relation' => 'OR',
                'product_new' => array(
                    'key' => '_product_new',
                    'value' => '1',
                ),
                'product_almost_new' => array(
                    'key' => '_product_almost_new',
                    'value' => '1',
                ), 
                'product_old' => array(
                    'key' => '_product_old',
                    'value' => '1',
                )
            )));

        /*THIS HAS NO EFFECT*/
        $q->set('orderby', array(array( 
                'product_new' => 'DESC',
                'product_old' => 'DESC',
                'product_almost_new' => 'DESC',
            )        
        ));

    }

}

I want the products to then be displayed in the following order:

1. product_new
2. product_old
3. product_almost_new

I am using $q->set('orderby', array(......) but this is having no effect. My products are ALWAYS being ordered product_old , product_almost_new , product_new .

Any ideas why my 'orderby' is not working? Any help is appreciated.

Answer 1

You did all right except one thing. You have used array in array in orderby which is not correct. Here is how it should look like:

$q->set('orderby', array(
                'product_new' => 'DESC',
                'product_almost_new' => 'DESC',
                'product_old' => 'DESC',
            )        
        );