FileMaker Pro 4.1 Mac User's Guide

2-20 FileMaker Pro User’s Guide
Stored and unstored calculation results
Functions
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You can have FileMaker Pro:
1 perform a calculation whenever the data that the calculation is based
on changes, and store the result in the calculated field (a stored result)
1 perform a calculation and display the result only when you need to
use the data—for example, to browse or print records—(an unstored,
or virtual, result)
In most cases, FileMaker Pro makes a field stored when you define the
field. You can change the storage type to unstored.
Keep these points in mind:
1 FileMaker Pro makes a calculated field unstored when its formula
refers to a global field, an unstored calculated field, a related field, or
a calculation that includes a summary field.
1 Stored results use more disk space. Unstored results take more time
to calculate.
Choose FileMaker Help Index from the or Help menu, and then type:
E calculation fields
A function is a predefined, named formula that performs a specific
calculation and returns a single, specific value. You type only the
function, and FileMaker Pro performs the calculation it represents. You
can use functions by themselves or combine them with other functions
or expressions. For information about specific functions in
FileMaker Pro, see appendix C, “Summary of functions.”
Choose FileMaker Help Index from the or Help menu, and then type:
E functions, using
Writing formulas for calculation fields
1. Create a file, or choose Define from the File menu and then choose
Fields.
2. In the Define Fields dialog box, for Field Name, type a name for the
field.
3. For Type, select Calculation, and then click Create.