Database fields?

Concepts

What are the different kinds of database field?

When you define a database field you will have the chance to specify the Format or type of the field. The different data types that Access supports are:

Text
Memo
Number
Date/Time
Currency
Auto Number
Yes/No
OLE object
Hyperlink
Lookup Wizard

The field type determines how the values in that field will be interpreted and displayed. For example, the value 2 formatted as a date looks like , but when formatted as a number looks like .

A field type isn't permanent; it can be changed after the database has been created. You should be aware, though, that once you have data in your database, changing the field type may require you to reenter the value in each record for the newly formatted field. This is another reason planning is important when you are defining a database. Insufficient planning in the beginning can create more work later on.

Why isn't all data "Text" type?

If all data was of type text sorting, selecting, and calculating on a field would be more difficult. Consider the two values, and . Sorted as text, April would come before January, but you would most certainly expect January 14, 1997 to come before April 1, 1997. Calculations on a field cause a similar problem.