Firebird SQL query or script needed

We need a query or script to return some needed data Here are the relevant [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] We are only concerned with records from creditaccount where open=1 and accountnumber=7 We need to see * cardnumber * dateissued * creditlimit * balance balance will come from creditlimit minus the sum of the [login to view URL] where the [login to view URL] = [login to view URL] In other words, creditaccount is a list of accounts checkpayment is a list of payments made using the accounts creditaccount will have one record for the account checkpayment will have one or more (sometimes none) payments corresponding to each account