I have a table with subscriptions, transactions and transaction types. Subscriptions are comprised of transactions of various transaction types. For each subscription I would like to create a counter on a transaction level to track the number of certain transaction types that the subscription has made. I'm able to use the autonumber function to do this, however, unable to limit it to only numerate transactions with a specific subscription. Ideally, I would group by subscriptions, then by transactions in ascending order and assign a number to each transaction which meets specific conditions.
Explanation may sound confusing so I've attached an example to work with.
I think I'm pretty close to getting this to work, so if anyone has the time to give it a look it would be much appreciated.