Microsoft Office Tutorials and References
In Depth Information
Access Data Types
The field you’re using
To set a maximum length,
choose your field, and then
click the Field Size box in
the Field Properties list
(shown here). (All the field
properties you need in this
chapter are on the General
tab.) When you click a field
property box, that field
property’s description appears on
An explanation of the
field size setting
Up to speed
Maximum Length Guidelines
Here are some recommended maximum lengths:
• First names and last names. Usually, 25 characters
handles a first name, while 50 characters plays it safe
for a long, hyphenated last name.
• Middle initial. One character. (Sometimes common
sense is right.)
• Email address. Go with 50 characters. Email
addresses closer to 100 characters have turned up in
the wild (Google “world’s longest email address” for
more), but they’re unlikely to reach your database.
• Cities, states, countries, and other places.
Although a Maori name for a hill in New Zealand tops
out at over 80 characters (see http://en.wikipedia.
org/wiki/Longest_word_in_English ), 50 is enough
for most practical purposes.
• Street address. A street address consists of a
number, followed by a space, then the street name,
another space, and the street abbreviation (like Rd or St).
Fifty characters handles it, as long as you put postal
codes, cities, and other postal details in other fields.
• Phone numbers, postal codes, credit card
numbers, and other fixed-length text. Count the
number characters and ignore the placeholders, and set
the maximum to match. If you want to store the U.S.
phone number (123) 456-7890, make the field 10
characters long. If you plan to accept international
numbers, you’ll need to allow for up to 15 digits.
• Description or comments. Specifying 255
characters fits three or four average sentences of
information. If you need more, consider the Memo data type
instead (page 720).