FileMaker Pro 8: The Missing Manual

Chapter 9. Introduction to Calculations

Fields and layouts form the basis of every database: You can’t have a FileMaker database without them. Using just what you know so far, you can build all kinds of useful systems that store data, from an address list to a catalog of products.

But if you want to do the really useful stuff with your data—total an invoice, analyze trends, compare figures—you need specific tools. For those tasks, FileMaker provides Calculation fields and a whole drawer full of functions that let you examine, compare, and combine field values. And calculations aren’t just limited to number-crunching tasks. You can use them to find out about the computer your database is running on, track who’s logged into the system, monitor their privileges, and then perform logical tests based on what you find. You’ll start by learning how FileMaker handles calculations, and then you’ll see how some common functions can take your database up to a new level of power.

Understanding Calculations

A calculation is a mathematical formula: It shows how different things combine to come up with an answer. But even if you hated algebra class, don’t close the book yet! Instead of the Xs, Ys, and Zs of the math world, FileMaker lets you use your own fields to supply your formula with data—a much more intuitive approach.

FileMaker calculations can also do more than just math. For starters, you can do calculations on time, date, timestamp, container, and text fields, too. (See the box on Section ...