Store currency and volume in database

We are creating an enterprise application for fuel, and I am fighting with my DBA about the proper way to store volume and currency in the database. We have 2 main arguments. The first argument is whether we should store costs in the database in $ and convert in the presentation layer, or to store the amount and currency in the database. We sell product from the US in dollar but depending on the customer we may invoice in Euro. Our second argument is the same, execept with volume and UOM. We often purchase product by BBL but sell/transfer by gallon, or Ton.

please tell us the best practice for our dilemma.

Personally, I would never store a measure in different currencies; particularly if it's in one column. This would mean that for every calculation your application does, for instance a SUM on the amount over a certain period over different customers, it would have to convert every single value before you can do an aggregation. But of course this depends on what the application does. What would be the advantage

I assume the client application does not communicate with SQL Server by ad hoc queries, just by view and/or stored procedures in which you can provide the client application with the data presented in any way which is needed.