When you learned about tables, fields, and relationships in the previous chapters, you dabbled in FileMaker’s calculation dialog box. Most people first encounter the Specify Calculation window when they’re creating a calculation field, so it’s easy to think that’s the only place it’s used. True, writing formulas for calculation fields is probably the most common use of FileMaker’s calculation engine (that’s the fancy name for the code that handles math for your database), but it’s far from the only use, as you’ll see later in this chapter.
No matter where you run into the Specify Calculation window, it works the same way. You use that window’s field list, operators, and predefined functions to tell the calculation how to find the value you need. This chapter tells you how the basic concept works.
While calculations can make your database total invoices, analyze trends, and calculate dates and times, they aren’t 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.
Way back on Creating a Simple Calculation, you saw how to create a field that’s defined as a calculation. A calculation is a mathematical ...