Database Reference
In-Depth Information
Privilege Sets can use calculations to limit access to tables, records, and fields.
Chapter 18 tells you how to use calculations for tighter database security.
Creating a Calculation
As the Jobs database now stands, when you add line items to an invoice, you have to type the
quantity and price for each item. Then you have to multiply them together to get the exten-
ded price and then you have to type the result. In this section, you'll learn how to tell
FileMaker to do all that work for you, using a calculation that names your fields and uses
computer shorthand to do the math:
1. In the Jobs database, choose File Manage Database and then make sure you're
on the Fields tab. From the Table pop-up menu, choose Line Items .
That's the table with your Extended Price field in it.
2. In the field list, select the Extended Price field. From the Type pop-up menu,
choose Calculation and then click Change .
FileMaker warns you that when it converts the field, it changes (read: overwrites) any
information already in the field. See Figure 9-2 .
Figure 9-2. This warning is serious. Your new calculation overwrites existing data when
you close the Manage Database window. But you're safe until you click OK to this warning
and in the Manage Database dialog box. If you change your mind and don't want the cal-
culation after all, just click Cancel instead, and you get the chance to discard all the
changes you've made to this field.
3. Click OK .
The Specify Calculation dialog box appears, as shown in Figure 9-3 .
4. In the Calculation box, type Quantity * Price Each .
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