Database Reference
In-Depth Information
Figure 12.16. Completed View Specifications sheet for the CUSTOMER CALL LIST
view
Reviewing the Documentation for Each View
Onceyou'vecompletedthetaskofdefininganddocumentingeachview,reviewallofyour
views once more—ensuring that the quality of the information each view provides is well
worth the effort. As you review each view, keep the following points in mind.
•
Make certain that you've defined the view properly.
Think about the information
the view should provide. Are you establishing the correct type of view for the re-
quired information? Did you use the appropriate base tables to define the view?
Did you include all the necessary fields within the view's structure? Are
only
the
necessary fields included in the view's structure?
•
Make certain that the calculated fields you've created are suitable for the view.
Do
they provide pertinent and meaningful information? Do they serve to enhance the
manner in which the view displays its data?
•
Make certain that the filters will retrieve the required records.
First of all, do you
need a filter for this view? If the answer is yes, do you know exactly which records
you want the view to display? Do you believe that the filter will work correctly?
•
Above all, make certain that you have a view diagram and View Specifications
sheet for each view
. This documentation will be very useful when you finally im-
plement the database in an RDBMS.
Case Study
Your work on Mike's database is finally nearing an end. You meet with Mike and his staff
todeterminewhetherthereisaneedtoestablishviewsforthedatabase.Theagendayou've
set up for the meeting involves the following steps.
1.
Review the notes you've compiled during the design process.
2.
Review each of the various samples you gathered during the early stages of the
design process.
3.
Examine the subjects represented by the tables in the database.
4.
Analyze the table relationships.
5.
Review and study the business rules.
As the meeting progresses, you identify several views that you need to define, including a
PREFERRED CUSTOMERS view and a VENDOR PRODUCT COUNT view. The first
view will provide the name and phone number of each customer who has a “Preferred”
