Page 195 - Using MIS

Q1 What Is the Purpose of a Database?
Q1
163
“Addison, what are you doing? We don’t know anything about creating queries . . . ”
Drew whispers.
“No, Drew, you don’t know anything about creating queries. This isn’t hard. If he
gives us the data, I can munge around in Access to make the report. It’s just for us;
we’re not gonna post it on our Web site.”
“Seems hard to me, but I’ll go along. I hope that’s not a mistake.”
“It won’t be. Just watch.”
Chapter preview
Businesses of every size organize data records into collections called databases. At
one extreme, small businesses use databases to keep track of customers; at the other
extreme, huge corporations such as Boeing and Verizon use databases to support
complex sales, marketing, and operations activities. In between are businesses
such as AllRoad Parts that use databases as a crucial part of their operations. Such
businesses have a small staff of professionals and can’t always support special needs,
like those of Addison and Drew at AllRoad Parts. To obtain the one-of-a-kind reports
they need, Addison and Drew need to be creative and adaptable.
This chapter discusses the why, what, and how of database processing. We begin
by describing the purpose of databases and then explain the important components of
database systems. We then overview the process of creating a database system and
summarize your role as a future user of such systems.
Users have a crucial role in the development of database applications. Specifically,
the structure and content of the database depend entirely on how users view their
business activity. To build the database, the developers will create a model of that
view using a tool called the entity-relationship model. You need to understand how to
interpret such models because the development team might ask you to validate the
correctness of such a model when building a system for your use. Finally, we describe
the various database administration tasks.
This chapter focuses on database technology. Here we consider the basic
components of a database and the functions of database applications. You will learn
how Addison used database queries to solve the AllRoad Parts problem in Chapter 9.
What Is the Purpose of a Database?
The purpose of a database is to keep track of things. When most students learn that, they won-
der why we need a special technology for such a simple task. Why not just use a list? If the list is
long, put it into a spreadsheet.
In fact, many professionals do keep track of things using spreadsheets. If the structure of the
list is simple enough, there is no need to use database technology. The list of student grades in
Figure 5-1, for example, works perfectly well in a spreadsheet.
Suppose, however, that the professor wants to track more than just grades. Say that the
professor wants to record email messages as well. Or perhaps the professor wants to record both
email messages and office visits. There is no place in Figure 5-1 to record that additional data. Of
course, the professor could set up a separate spreadsheet for email messages and another one
for office visits, but that awkward solution would be difficult to use because it does not provide
all of the data in one place.