hi all,
I'm trying to keep track of financial transactions, including customer
account balances in my database. In this database customers can
purchase and return (refund) goods. Purchases/Refunds may take place
using cash,credit cards,pos systems, or using the customers account
(credit/debit).

My proposed solution is this:

The following two tables are not up for discussion, I've simply added
them to give a clearer picture.

Table Booking: this is a table to allow customers to put a hold on
goods,who the goods are for, and the sale price (there is a reason for
the sale price being here but I dont want to get into that). It would
also have the moneytransferId (fk,see below).

Table Refund: Refund details including refunded amount, and
moneytransferId(fk)

The financial tables ...

Table CreditTransfer : A table to allow customers to top up their
accounts
unique id,
moneytransferid (fk),
$amount

Table MoneyTransfer : A Generic table
unique id,
time and date of transfer,
type of transfer (purchase/refund/credit account)
mode of transfer (cash,credit card,pos,account)
accountid(fk)

Table CreditCard : A table holding credit card details.

Table POS : A table holding pos details if required.

The system will encourage the same 'mode of transfer'
(cash/creditcard/pos..) for the refund as was used in the purchase -
so if you buy using your creditcard the system will try to refund the
money onto the same credit card.

And finally
Table Account : Account details

Table AccountBalance: A table that expresses the correct account
balance at that point in time. A row may be created every month.
accountid
timeanddate
amount

Is this design sound? Please post especially if you have financial db
experience.

Thanks,
news