$data = db_query("SELECT productID, in_stock, sort_order, Price, name FROM (SELECT productID, in_stock, sort_order, Price, name, COUNT(DISTINCT optionID) AS count FROM ".PRODUCTS_OPTIONS_SET_TABLE." JOIN ".PRODUCTS_TABLE." USING(productID) WHERE enabled=1 AND Price>=$price_from AND Price<=$price_to AND $addonCat$addonStock$addonSearch AND variantID IN (".implode(',',$search).") GROUP BY productID ) AS t WHERE t.count=$POSTcount ORDER BY $filtersort");
Поля in_stock, sort_order, Price, name добавлены так как по ним происходит сортировка