Introducing the Sample Database

The bookbiz database is not a real-world database but simply a learning tool. Its primary purpose is to provide you with a small collection of interesting data to manipulate as you study SQL syntax and semantics.

The bookbiz database is about a fictitious publishing company that has three subsidiary publishing lines. The database stores information that editors, administrators, and executives might want about books, their authors, their editors, and the company's financial arrangements. This database can produce many kinds of reports summarizing current sales, comparing different book lines, discovering which editors work with which authors, and so on. In real life, the database would probably support many other uses and many more reports.

Users of the bookbiz database can pose many different questions, including these:

• Which authors live in California?

• Which business books cost more than $19.95?

• Who has written the greatest number of books?

• How much do we owe the author of Life Without Fear?

• What's the average advance paid for all the psychology books?

• How would increasing the price of all the cookbooks by 10 percent affect royalty payments?

• How are sales of the computer subsidiary doing?

• Which books are most popular?

As the database designer, don't try to just imagine which questions are most important to the future users of the database you're designing. You need to research users' needs by reviewing current data collection and retrieval methods and by interviewing your users individually, in groups, or both.

One important area of investigation is the organization's business rules and policies that affect the data. The policies of the publisher for which bookbiz is being designed include these:

• An author may have written more than one book.

• A book may have been a collaborative project of more than one author.

• The order of the authors' names on the title page is crucial information, as is the percentage of the royalties each will collect.

• An editor may be working on more than one book, and a single book may be assigned more than one editor.

• A sales order may be for one or many titles.