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)