help!!! with macros!

[newuser]

hi,
How would i go about creating a setvalue macro using the expression builder
to deduct a value on a form from a value in a table?? for example i have a
database based on a theme park which uses a points based system, in which the
customer reserves their rides using the database.Now on the reserve rides
form each ride has a particular points value,how would i deduct this amount
from the customer table from thier points outstanding field.??? cheers!

 

[Steve Schapel]

Newuser,

You wouldn't use a SetValue action for this. You could make an Update
Query, and then use an OpenQuery action in your macro to run the update.
But it seems your question reflects a basic misconception. Can you
consider a revision of your database design, or is it set in concrete?
You shouldn't have a Points Outstanding field in the table. This is a
derived or calculated value, and is not applicable in a database table.
You should have a points transactions table, related many-to-one to
your customers table, where you record points earned and points
redeemed, and then you can easily obtain the customer's points
outstanding via a query whenever you need it.