632598256894

Database Software
A database is a collection of data stored in such a way that the user may create and identify
relationships among data. For example, a mailing list of one‟s customers might contain information
about each customer, each of his or her purchases, and everything about the individual sales
transactions themselves, including the price paid, who sold it, how paid, and so forth. This information
can be retrieved in a variety of ways, usually specified by the user at the time of execution. The user
might want a list of all customers who purchased a specific product between January and May, or
possibly a list of all products a customer has purchased, in aggregate, that were sold by a particular
salesperson. The number of possible combinations and permutations and ways in which one views the
data is limited only by the collection of the data and the imagination of the user. Database technology
has put the data of the firm in the hands of the worker. For example, using a database as just described
(customer purchases), the worker might like to know the total amount spent, as well as the number of
purchases for customers (from over 4,000 customers) who made more than one purchase. Exhibit 19.7
shows a user-developed query in Microsoft Access to extract that data, and Exhibit 19.8 shows the
first 27 of 94 records returned by Microsoft Access.
Exhibit 19.7 User-built query using Microsoft Access.