Database Reference
In-Depth Information
It also keeps you from jumping back and forth between different types of business rules,
which can often lead to confusion and some amount of frustration.
Working with Users and Management
Once again, you'll work with the representative group of users and management. Schedule
new meetings with them so that you can work together to define and establish the appro-
priate business rules for the database. Working as a group enables you to make certain that
the constraints imposed by the business rules you define are meaningful and that there is
no confusion or ambiguity as to the necessity of imposing each constraint. If you or any-
one in the group has some doubt about a constraint, you can discuss the effect it will have
on the field or relationship involved and the advantages and disadvantages of imposing the
constraint. You can then decide whether to keep the rule or disregard it completely based
on the results of your discussion.
Defining and Establishing Field-Specific Business Rules
Begin the process of establishing business rules for the database by working on field-spe-
cific rules. You define and establish each rule using these steps.
1.
Select a table.
2.
Review each field and determine whether it requires any constraints.
3.
Define the necessary business rules for the field.
4.
Establish the rules by modifying the appropriate field specification elements.
5.
Determine what actions test the rule.
6.
Record the rule on a Business Rule Specifications sheet.
Let's now take a look at each step in greater detail.
Step 1: Select a Table
Itdoesn'tmatterwhichtableyouselectfirstbecauseyou'lleventuallyapplythisprocedure
to every table within the database. If you choose a table with a familiar structure, however,
youcanfocusalittle moreonlearning thestepswithin theprocedure. Thisextra effortwill
pay dividends when you begin to work with tables containing fields that bear closer atten-
tion and examination.
Think about the subject the table represents and then pose these questions:
How does the organization use information based on or related to
this subject?
What relationships does this table have to itself or to other tables
in the database?
