ok forget the timestamp i just realized that it's not the best way to do what i imagined, i solved the date of the order by just inseritng into the table the date through a variable.
let me explain. i have a table "CART" that stores the items added temporarly and the the user has a button to order that items.
then i pass them from "CART" to "ORDERS" like this
$sql = "INSERT INTO orders(email, cod, qty, type, model, price) SELECT email, cod, qty, type, model, price FROM cart WHERE email='$login_utilizador'";
at this time i have to insert something that is equal to all of them and the can distinguish them so that the administrator can group the items in an order, this happens 'cause the user can make two orders in one day or even minute.
so i'm thinking that maybe a good way to do it would be to create a random number and inserting it into every row that contains an item when i do the query above.
how? any sugestions?