Microsoft Office Tutorials and References
In Depth Information
Formatting Fields with Field Properties
cyan, red, magenta, yellow, and white. In forms, conditional formatting is
available, and you can specify an expression to determine format —
displaying unshipped status in red, for example.
Setting the field size
Using the Field Size property correctly can keep your database efficient;
doing so keeps the field size as small as is practical, making for a smaller,
more compact database. For Text fields, the Field Size property can also
help you screen out incorrect data. If you know that you need only four
characters in a certain field, set the field size to 4; anything longer produces an
error message. (For more about screening out incorrect data, see Chapter 5
of this minibook.)
Book II
Chapter 2
Using the Field Size property for any of your Number fields is a little
more complicated, but again, using the shortest practical field size makes
your database more efficient.
Table 2-4 shows your choices for the field size of a Number field, listed from
the smallest amount of space required to store each value to the largest.
Table 2-4
Field Sizes for Number Fields
Setting
What It Can Hold
When to Use It
Byte
Integers from 0 to 255
When values are small
integers less than 256.
Integer
Integers from –32,768 to 32,767
For most fields that need
integers unless you need to store
values greater than 32,768.
Long
Integer
Integers from –2,147,483,648 to
2,147,483,647
When the Integer setting isn’t
enough.
Single
Numbers from about –3.4E38
to –1.4E–45 for negative
numbers and from about 1.4E–45 to
3.4E38 for positive values;
decimal precision to 7 places
For numbers with decimal
values. This field size holds
big numbers and lots of
decimal places; Double holds
even more. Generally
speaking, Single is sufficient, but
you can change the setting to
Double without losing data.
Double
Numbers from about –1.7E308
to –4.9E324 for negative
numbers and from about 4.9E–324
to 1.8E308 for positive values;
decimal precision to 15 places
For any values that Single
won’t hold.
(continued)
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