Code-Snippets-Functions/Execute a function on a child site/WooCommerce/make-coupon-code-sortable-coupon-list.txt

// Make column sortable
function filter_manage_edit_shop_coupon_sortable_columns( $columns ) {
    $columns['coupon_code'] = 'code';

    return $columns;
}
add_filter( 'manage_edit-shop_coupon_sortable_columns', 'filter_manage_edit_shop_coupon_sortable_columns', 10, 1 );

// Fires after the query variable object is created, but before the actual query is run.
function action_pre_get_posts( $query ) {
    global $pagenow, $post_type, $wpdb;

    // Only for coupons
    if ( $query->is_admin && $pagenow === 'edit.php' && $post_type === 'shop_coupon' && $query->get( 'orderby' ) == 'code' ) {
        // ASC OR DESC
        $asc_desc = $query->get( 'order' );

        // Get all coupon IDs
        $coupon_ids = $wpdb->get_col( "SELECT ID FROM {$wpdb->prefix}posts WHERE post_type = 'shop_coupon' ORDER BY post_name $asc_desc" );

        // Set
        $query->set( 'post__in', $coupon_ids );
        $query->set( 'orderby', 'post__in' );
    }
}
add_action( 'pre_get_posts', 'action_pre_get_posts', 10, 1 );