Relationships Graphs and ERDs

Chapter 5, "Relational Database Design," outlined some database theory that helps produce an ERDan entity-relationship diagram that shows the fundamental building blocks of a database system and the ways in which they relate. In Chapter 6, "Working with Multiple Tables," we showed how to use FileMaker's relationship tools to turn an ERD into a working FileMaker database. This might mislead you into thinking that the Relationships Graph is really the same thing as an ERD, and that the relationships you build there match one-to-one with the relationships you sketch out on your ERD.

In fact, there's a lot more to relationships in FileMaker. The Relationships Graph certainly handles all the structural relationships present on an ERD. But there are many other ways to use relationships in FileMaker. The ERD-based relationships are the structural core of any FileMaker database (or any relational database), but this chapter takes you beyond the core and shows you some other ways you can use relationships in FileMaker. It also delves further into the features of the Relationships Graph, and discusses different ways of organizing files, tables, and table occurrences in a FileMaker system.

Bottom line: The Relationships Graph is actually a superset of your ERD. It certainly has the ERD wrapped up in it, but it may well contain other important structures and relationships as well. Those techniques are the subject of this chapter.

Relationships as Queries