customer id, order id in invoice.php/date("U")

[zeberrun]

<td class="main"><?php echo (int)$oID; ?></td><td class="main"><?php $orders_query = tep_db_query("select customers_id from " . TABLE_ORDERS . " where orders_id = '" . (int)$oID . "'");?><?php echo $orders_query;?></td>

 

i can see the order id but customer id. error for order_id Resource id #43

 

i use date("U") function for random order_id, but gives 10 digits, too long, can i restrict with 8 digits or another functon?

 

regards