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
Integer value in the range of 0 to 255.
Integer value in the range of -32,768 to 32,767.
Integer value in the range of -2,147,483,648 to 2,147,483,647.
Numeric values with decimal places to seven signiﬁ cant digits — requires four bytes of storage.
Numeric values with decimal places to more accuracy than Single — requires eight bytes of storage.
Special identiﬁ er required for replication.
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
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.
• Click the Design View button on
the status bar to move to Design
view (Figure 1–68).
in Design view
for ID ﬁ eld