mpbm23 on "[Plugin: Skroutz.gr & Bestprice.gr XML Feed for Woocommerce] Can i add a custom field in xml?"

You can add a special field mpn2 on products and then on createsk.php file after

$onfeed =$wpdb->get_results($sql);

add

$sql = $wpdb->prepare(  "SELECT *
		FROM " . $wpdb->prefix . "postmeta
		WHERE <code>post_id</code> =" . $prod->ID . " AND <code>meta_key</code> LIKE 'mpn2';",0);
 $mpn2=$wpdb->get_results($sql);

and after

$product->mpn = NULL;            $product->mpn->addCData($sku->meta_value);

add

$product->mpn2 = NULL;            $product->mpn2->addCData($mpn2->meta_value);