1. Assuming I am building a database for a bank. How would I implement credit and debit transactions so that the running balance is computed correctly even though there are concurrent debit and credit transactions going on.
2. How would I also ensure that the zip code, city, and State code information entered into the database is correct
( I believe there is a pl/sql way of ensuring if not please describe the working of your procedure in structured english.)
with regard to the second quetion, you would use data from the us postal service to validate addresses. since they have such an interest in everyone getting the correct address, they sell products and listings to help with this
Technically, there are not "concurrent" transactions going on. No two transactions have exactly the same timestamp.
running balance is redundant data -- calculate it when needed, calculate it at close of business, but don't try to calculate it with each transaction.