FileMaker Pro 9: The Missing Manual

Replacing Data Using a Calculation

You can use calculations productively with the Records → Replace Field Contents command. This command tells FileMaker to visit every record in the found set, replacing the contents of one field with something new. When you first saw this command in Chapter 2, you entered a single value in every record. Sometimes, though, it’s more useful to have FileMaker use a calculation to figure out what should go in each record.

FREQUENTLY ASKED QUESTION: Validate Only If Field Has Been Modified

What is the “Validate only if field has been modified” checkbox for? I don’t remember seeing this in the Specify Calculation window before. For that matter, where did the Result Type pop-up menu go?

Good eye. The Specify Calculation window can show up in lots of places—when defining a calculation field, when specifying an Auto-Enter calculation, and so on—and it can change slightly in each case.

First, the Result Type pop-up menu shows up only when you’re defining a calculation field, since it can produce any data type. Since a validation calculation always has a Boolean result, there’s no need to ask you here.

In place of this pop-up menu, you often see some new option specific to the calculation type—like the “Validate only if field has been modified” checkbox in Figure 9-10.

Normally when you edit a record, FileMaker validates only the fields you actually change. Any field in the record that hasn’t been changed is accepted even if it violates the validation rule. ...