I've just started using Oracle 8 for my uni course and I'm currently stuck on a problem which should be very easy to solve but I do not know how.
The problem is I have to create a table where one of the attributes will only allow the user to enter a pre-defined data. E.g. for the Payment_Type in my Payment table, the user is only allowed to enter either cash, credit or direct credit, how do I enforce this?
Do I have to specify something in the create statements? Plz help.