Hi
i have the following tables: for readability i fill it with data so it's easy to understand what's needed
Orders Table

id  date              tourid    pax     ActivityID
1   01/04/2012      1          2           1
2   01/04/2012      2          1           2
3   01/04/2012      1          1           1
4   02/04/2012      1          1           3

Then i would like to maintain an Activity table, which is the Orders table grouped by Date and TourID as in:
Activity table:

ActivityID    Date           tourid     TotalOrders    TotalPax
    1          01/04/2012      1                3              4
    2          01/04/2012      2                1              1
    3          02/04/2012      1                1              1

I would like a stored procedure to do the following: when adding a new Order, either create a new activityID line, or update the quantities if there already is one. When modifying an order, modify the resuting ActivityiD accordingly. Finally, i would like to save the related ActivityID in the orders table.

Thanks
Jaime