function deleteCachedItemsContainingSongId(Song $song) { // get all items that refer this song $items = $song->items()->get(); $item_id_list = []; // get each item id into an array foreach ($items as $item) { # find item in cache array_push($item_id_list, $item->id); } // get all items in the cache with the same item_id's $cachedItems = PlanCache::whereIn('item_id', $item_id_list); $cachedItems->delete(); }