The most important part of creating a relational database is determining how you'll organize the data you've listed. The easiest way to visualize the task is to imagine your database as a series of spreadsheets. Each spreadsheet is a logical grouping of fields that belong together. Each individual column heading is a major category of information. Each row is a set of fields with entries in the columns. The column headings become the field headings in your database. Your mission is to match up the right set of column headings for each spreadsheet.The best way to start this process is to segment the information into categories, and avoid putting too many columns in each category so you don't go crazy working with too many variables at once or end up duplicating data. Look for modules of information that can be logically grouped (Figure 2.1).
Figure 2.1. The original list of possible data has been organized into logical groups.
Let's continue with the college database. We have a set of data called Students. In the Student table listing, we'd certainly have the student name. But there are so many other pieces of information about the student to consider! The key thing to remember is that, although all this information is important, not all of it belongs in the Student spreadsheet table. For example, the Dean's office probably already has a list of majors the college offers, broken out by the department that offers them. The Registrar's office certainly needs a separate database of courses for the student to choose from, as well as prerequisites for each class to prevent students from registering for a course they're not prepared to take. So these types of information are related to students, but aren't parts of their primary information.What does belong? Only the information that will remain intrinsic to the student no matter what happens during his or her college career: ID, birthdate, addresses, phone numbers. Course-related information belongs in a different table, grade and credit information might belong in another. It's easier to create a relationship between two tables to bring sets of information together than it is to separate information you've crammed together in one table. For example, although you'll need to know the courses students take and their grade point averages, the course information itself should be separate from the student records. The grade point average can be found by creating a calculation and a summary field that links to the database where final class grades are kept (Figure 2.2).
Figure 2.2. Although the keyed data is part of the student information, it logically belongs in a separate file or table in the database.
Chapter 6, "Creating Relationships," you will learn FileMaker techniques to create such relationships. For example, we could create a portal to list all of the courses for that student in a layout in the Student database, and use a summary of related fields to total the number of credits each student has earned (Figure 2.3).
Figure 2.3. The Student Data file has a layout that includes a portal listing all the courses in which the student is currently enrolled.
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