From: "robert keith
To: "Jim Booth
Subject: Re: business rules

Hey Jim,
I hope you don't mind if I email you with this question. I did not
want to seem like a dummy infront of everybody at the universal
thread, but what are "business rules"?

thanks
robert keith
thread number 194522



From: "Jim Booth
To: "robert keith
Subject: Re: business rules

Robert,

You could certainly ask this in the UT as there are probably many
others who are thinking the same thing but are afraid to ask.

Business rules are simply that set of rules governing what constitutes
Valid data that are a result of the specific business practices and
not a Result of the data schema definition. For example, assume you have a client that does business in NY, NJ, and CT and they tell you they don't want the user to be able to enter any other states. You create a customer table that has a state field in it, the domain for the state field is any two character state abbreviation, but the business rule is more strict than that. If you enforce the business rule at the database level you limit the future growth of the company (it would require a change to the database schema). If you, instead use a business layer in the application that acts as a go between for the interface and the data you can enforce the business rule there and leave the data schema allowing all states.

JimB