Re: Trigger :Add an old value with the new value

[Peter Brawley]

There seems to be a design problem---you will need to keep a record of an individual's current payment, and also a record of her total payments; the usual solution is to keep a total_paid column in an `account` table, store individual payments in another `transactions` table, and update the account sum when there are new transactions. Then a Trigger on transactions would say ...

update account
set total_paid = total_paid + new.paid
where account_id=new.account_id;