Woocommerce WP_Query post__not_in problem

Question

I want to exclude sale products from output related products.

In $args i have field post__not_in where i want to output array of values from wc_get_product_ids_on_sale(); function.

Code before $args

$related = $product->get_related( $posts_per_page );    
$product_ids_on_sale = wc_get_product_ids_on_sale();

After i wrote args

$args = apply_filters( 'woocommerce_related_products_args', array(
            'post_type'            => 'product',
            'ignore_sticky_posts'  => 1,
            'no_found_rows'        => 1,
            'posts_per_page'       => $posts_per_page,
            'orderby'              => $orderby,
            'post__in'             => $related,
            'post__not_in'         => $product_ids_on_sale,
        ) );

But in frontend i see products not in sale and in sale

I try to echo $product_ids_on_sale it returns Array As i understand, i need to return each value from array $product_ids_on_sale separated with , Than i try to write foreach like

$product_ids_on_sale = wc_get_product_ids_on_sale();
         foreach($product_ids_on_sale as $result) {
            echo $res,',';
        }

But echo is not i want. I need to return it Also i try to write to 'post__not_in'

array_merge( array( 0 ), wc_get_product_ids_on_sale() )

Didn't help...

Please help me to exclude sale products!

Answer 1

If you have both post__in and post__not_in as input arguments for WP_Query, then only post__in is activated. See the source here.

If you need to exclude IDs from the post__in, you should do it before passing on the array.