$s = preg_split('/s+/', $request->keyword, -1, PREG_SPLIT_NO_EMPTY);

$items =   Items
            ::join('ic.itemunits as iu', function($join) {
                $join->on('items.itemcode', '=', 'iu.itemcode');
                $join->on('items.defaultvendorcode', '=', 'iu.vendorcode');
            })
            ->select('items.itemcode', 'items.picturecode', 'items.description')
            ->where(function ($query) use ($s) {
                foreach ($s as $value) {
                    $query->orWhere('items.description', 'like', "%{$value}%");
                    $query->orWhere('items.itemcode', 'like', "%{$value}%");
                    $query->orWhere('iu.itemcode', 'like', "%{$value}%");
                }
            })
            ->get();