Microsoft Office Tutorials and References
In Depth Information
Chapter 3: Designing Your Database the Relational Way
After you use Access to create a table, you can really get busy — entering,
editing, deleting, and sorting the records in various ways, and printing many
types of reports (including columnar reports, forms, summaries, mailing
labels, and form letters). Access allows you to create as many tables as you
need in your database.
Designing a database means deciding (for openers) what tables your
database needs to include and what fields are in each table. At the most basic
level, it means designing the needed forms and, most likely, reports. This
process is the computer equivalent of designing the form or file card on
which you write the data, specifying which blanks need to be filled in and
which are optional.
Fields can be different data types, depending on what kind of information you
want them to store. Some fields contain textual alphanumeric information,
such as a last name or street address. Other fields contain numbers, such as
someone’s age. Others contain logical information — a yes or no regarding
some condition. Still others contain dates or times, such as the date when
the record was added to the database. Table 3-1 lists the Access data types.
Commonly Used Data Types for Fields
What It Holds
This data type is for short chunks of text up to 255 characters
or special codes that contain non-numeric characters, such as
phone numbers (xxx-xxx-xxxx) and zip codes (xxxxx-xxxx) that
require parentheses and hyphens, which aren’t allowed in numbers.
A Long Text field is like a Short Text field, but it allows more
characters — up to 65,536 of them. A Long Text field can contain rich
text (see the next item), and you can set it to Append Only so that
it can accumulate text notes without allowing the user to delete
what’s already there.