Microsoft Office Tutorials and References
In Depth Information
To Modify the Primary Key and Field Properties
Fields whose data type is Number often require you to change the fi eld size. Table 1–3 shows the possible fi eld
sizes for Number fi elds.
Table 1–3 Field Sizes for Number Fields
Field Size
Description
Byte
Integer value in the range of 0 to 255.
Integer
Integer value in the range of -32,768 to 32,767.
Long Integer
Integer value in the range of -2,147,483,648 to 2,147,483,647.
Single
Numeric values with decimal places to seven signifi cant digits — requires four bytes of storage.
Double
Numeric values with decimal places to more accuracy than Single — requires eight bytes of storage.
Replication ID
Special identifi er required for replication.
Decimal
Numeric values with decimal places to more accuracy than Single — requires 12 bytes of storage.
Because the values in the Rate fi eld have decimal places, only Single, Double, or Decimal would be possible
choices. The difference between these choices concerns the amount of accuracy. Double is more accurate than Single,
for example, but requires more storage space. Because the rates are only two decimal places, Single is a perfectly
acceptable choice.
In addition to changing the fi eld size, you should also change the format to Fixed (a fi xed number of decimal
places) and the number of decimal places to 2.
The following steps move to Design view, delete the ID fi eld, and make the Recruiter Number fi eld the
primary key. They then change the fi eld size of the Rate fi eld to Single, the format to Fixed, and the number of
decimal places to 2.
1
Click the Design View button on
the status bar to move to Design
view (Figure 1–68).
Primary Key
button
Recruiter table
in Design view
row selector
for ID fi eld
Figure 1–68
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