n
Company Setup:
This displays a form that contains information used by the entire sys-
tem. This is used when you need global values such as your company name (Access Auto
Auctions in this example) or other information that can be used by the entire application.
Understanding the Data Tables
Data is the most important part of any system and in Access (as well as every other database man-
agement system), data is arranged into logical groupings known as
tables.
Tables help define the
structure of the data, as well as hold the data itself. Tables are related to each other in order to pass
data back and forth and to help assemble the chaos of data into well-defined and well-formatted
information.
The diagram in Figure FM-2 displays the table schema in the Access Auto Auctions example. As
you will learn in Part I of this book, the lines, arrows, and symbols between the tables mean some-
thing important and communicate to the developer how the data interacts. You’ll learn terms like
table, field, record, relationship, referential integrity, normalization, primary keys,
and
foreign keys
as you
begin to understand how tables work within a database.
FIGURE FM-2
The Access Auto Auctions relationship diagram
The example database consists of the 11 core tables shown in Figure FM-2. Many of the smaller
tables are
lookup
tables whose sole purpose is to provide a list of valid selections. The larger tables
hold data used by the database application itself. All of these tables include a number of data fields
that are used as the definitions of the data. The lines between the tables show how tables are related:
n
tblSales
:
Contains fields for the main part of the sale. This includes information that
occurs once for each sale, such as the invoice number, dates of the sale, the buyer ID (which
links to the
tblContacts
table to retrieve information about the buyer including taxing
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