Where to find Bank Account field? and other Payment fields
For bank account and other fields, PaymentApplication table holds these fields. Use DESCRIBE PAYMENTAPPLICATION to find the column you are looking for. Bank Account is cashaccountingcodeid
Re: Where to find Bank Account field? and other Payment fields
For bank account fields like default Payment Method, Payment Gateway, Currency etc., use Payment Object.
Example: Select * from Payment Limit 1
In this, 'PAYMENTMETHODID' is default payment Method, 'GATEWAY' is Payment Gateway.
Also you can access these fields using Reporting under Account Data Source.