Database Reference
In-Depth Information
Figure 9-8. When you first create a record, the fields referred to in your calculations are usually
empty, so your calculation results are blank until you enter data in at least one field that's referen-
ced in the calculation. Turning off the “Do not evaluate if all referenced fields are empty” option
and then editing the calculation displays a “0” in the field instead. Use the same technique on the
Line Items::Extended Price field if you want a “0” to show there, even when both Line Items::Price
and Line Items::Quantity are blank.
For example, it would be nice if your invoice's Date Due field automatically showed a date
30 days after the date of the invoice itself. But sometimes you may want to make an invoice
due earlier or later. If you make the Date Due field a calculation field, then you don't have
this flexibility. Use a normal Date field with an
auto-enter calculation
.
Here's how to create an auto-enter calculation:
1.
Bring up the Manage Database window and then switch to the now-familiar
Fields tab. From the Table pop-up menu, choose Invoices
.
The fields from the Invoices table appear.
2.
Select the Date Due field in the list and then click Options
.
