Database Reference
In-Depth Information
Maintain data integrity
6
IN THIS CHAPTER, YOU WILL LEARN HOW TO
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Specify the type of data.
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Set the field size.
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Restrict the format of data.
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Validate the data.
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Allow only values in lists.
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Allow only values in other tables.
Depending on how organized you are, you might compare a database to a file cabinet into
which you toss items such as bills, receipts, statements, and a variety of other paperwork for
later retrieval. The cabinet does not restrict what items you can place in it (unless they are
simply too big to physically it) or impose any order on the items. It is up to you to decide
what you store there and to organize it so that you can find it the next time you need it.
When you create a database by using Microsoft Access 2013, you can set properties that
restrict what data can be entered and you can impose a structure on the data to help
you keep the database organized and useful. For example, you can prevent employees
from entering text in a Price field, and you can require a simple “yes” or “no” answer in a
Signature Required field.
In this chapter, you'll restrict the type, amount, and format of data allowed in a field. You'll
create validation rules that accept only data that meets specific criteria. You'll also use look-
up lists and lookup fields to limit the possible values allowed in a field.
PRACTICE FILES
To complete the exercises in this chapter, you need the practice file
contained in the Chapter06 practice file folder. For more information, see “Download
the practice iles” in this topic's Introduction.
