I'm new to report writing and I'm looking for some advice on where the responsibility lay for calculating data. Should calculated fields be handled by the initial app/database server pre-import, or by ZOHO from the raw data once imported?

Let's use a simple example. I have two tables, related to one another. Customers and orders, each order has a customer, each customer could have many orders.

Say I want a field that gives me a count of the number of orders each customer has, and others fields which tell me the total or average amount that each customer has spent.

Should I be calculating these values in my app before exporting the data? Or can/should ZOHO be used for calculating this?

Thanks for any advice you can offer,

Robert