total fields in both tables in a 1:many join

[adam island]

i have 2 tables. orders and order items. i want to find the total value of the items sold and the total order total (which would be different than product value due to taxes and shipping) is there a way to do this.

orders
------
id
date
total

orderitems
------
id
order_id
value



i can't say "select sum(orders.total), sum(orderitems.value) from orders, orderitems where orders.id=orderitems.order_id" because once they join, if there are 2 items in an order, they order.total is added twice for that order, making the final value way too high.