Use custom meta data in a WC_Product_Query on Woocommerce 3

To handle product custom meta data in a WC_Product_Query (located in wp_postmeta table), it's quiet simple and works, as explained in the very last paragraph of the related documentation.

But it doesn't handle multiple values and comparison arguments like in a WP_Query, if you don't set them in the function that extend the meta_query.

For a custom product meta key like _volume to handle the volume taken by a product in m3 (cubic meters), the following code will enable that custom meta_key with a specific compare argument "bigger than":

add_filter( 'woocommerce_product_data_store_cpt_get_products_query', 'handling_custom_meta_query_keys', 10, 3 );function handling_custom_meta_query_keys( $wp_query_args, $query_vars, $data_store_cpt ) {    $meta_key = '_volume'; // The custom meta_key    if ( ! empty( $query_vars[$meta_key] ) ) {        $wp_query_args['meta_query'][] = array(            'key'     => $meta_key,            'value'   => esc_attr( $query_vars[$meta_key] ),            'compare' => '>', // <=== Here you can set other comparison arguments        );    }    return $wp_query_args;}

Code goes in function.php file of the active child theme (or active theme).

Now you will just make your query on this custom _volume meta key based on the specific 'compare' argument, to get all products that have a volume bigger than '0.2':

$queried_products = wc_get_products( array( '_volume' => '0.2' ) );

Tested and works.

As you can see, you can continue using a WP_Query as many Woocommerce developers still do or even SQL queries through WordPress WPDB Class…

The announced revolution around this is not going to come soon and I suppose that they will extend WC_Product_Query and WC_Order_query like WP_Query with many more features and possibilities.

You can add this little function to fix it all :

add_filter( 'woocommerce_product_data_store_cpt_get_products_query', static function($wp_query_args, $query_vars, $data_store_cpt){    if ( ! empty( $query_vars['meta_query'] ) ) {$wp_query_args['meta_query'][] = $query_vars['meta_query'];}    return $wp_query_args;}, 10, 3 );

Now just pass meta_query to the wc_get_products and it supports it :).They probably should hire me lol.