| Lesson 3 || The subject approach to database design |
|Objective || Describe the subject approach to database design. |
Describe Subject Approach to Database Design
In general, there are two ways to approach database design.
- One is to focus on the subject matter with which the database is concerned, for example, how it will be organized and displayed;
- the other is to focus on the application in which the database will be created and viewed.
Subject Approach to Database Design
In the subject approach to database design, all the tables in a database store data according to subject matter.
A large company, for example, might have a database devoted to the sales department. Such a database might have tables devoted to customers, orders, discounts, and so forth. Other databases in the same company might be devoted to personnel, accounting, marketing, etc.
The subject approach
Just as each table in a database is devoted to one specific subject, in the subject approach the multiple tables in a database relate to a single subject area.
The subject approach to database design is called a top-down design because it follows the four-step order illustrated in the following Slideshow.
Use the forward and back arrows to scroll through the images.
1) Business objects are identified and described.
2) Business objects are grouped according to subject.
3) Databases are created for each subject area.
4) User applications are created to interact with databases.
Top Down Design
Even if you were designing a database for a small company, the subject approach would dictate that you create three small databases if you identified three distinct subject areas.
The next lesson introduces the application approach to database design.
Before moving on to the next lesson, click the Exercise link below to check your understanding of the subject approach to database design.
Designing Subject Database