Help with a bit of logic please

rocketman

I need to make a retrospective change to a financial transaction file.

At the moment a members balance is calculated simply by a rule in the BO that SUMs all the transactions that are referenced to that member.

This is fine until the time comes when I get some corruption in the database that would clobber this approach. Also (and more importantly members have asked for a different style of statement that is more like a bank statement ie the value of the transaction and a closing balance at the end of the transaction

Example
TX Date This transaction Curr Bal
17/12/2010 Bar Bill - £ 5.00 - £ 5.00
18/12/2010 Flying Fee - £27.50 - £32.50
19/12/2010 Payment + £50.00 + £17.40

So I'm thinking what I need to do is create a new attribute - say TX.Bal, then for each member ripple through the transactions one at a time and calculate the balance for the current transaction as being the balance from the previous tx + the total from the current transaction.

Just a bit stumped as to how to go about this in AwareIM

tford

Assuming each transaction has a sequential transaction number (Nbr attribute):

TX.Bal=SUM TX.Amt WHERE (TX.Nbr<=ThisTX.Nbr)

You may want to set this rule for dynamic calculation.

rocketman

Hi Tom, thanks for the post.

I see the logic of the statement. Given this is a retrospective one off fix, I'm now thinking my action should be:

Process 1:
Find all members
Process 2

Process 2:
Find transactions where transactions in Members.TX
Process 3

Process3:
TX.Bal=SUM TX.Amt WHERE (TX.ID<=ThisTX.ID)

Never done a triple whammy before. do you think this will work or will it fall out after the first member

Going forward, I think i've workd out the rules for NEW transactions, It's just the retrospective I was having difficulty with

tford

Let's assume your rule on the TX BO now includes taking the Member ID of the transaction into account when calculating the balance for any one transaction:

TX.Bal=SUM TX.Amt WHERE (TX.ID<=ThisTX.ID AND TX.MemberID)

This rule would then apply to both new transactions & existing transactions.

To get the rule to fire for all the old transactions, run a 1 time process:

FIND ALL TX
UPDATE TX