Overview

Transforming a data model into a database schema is not easy, but it's not going to put another person on the moon either. The techniques for turning an ER model into a relational model are well understood [Teorey 1999, Chapter 4]. Transforming a UML data model into a relational database uses these techniques and adds some more to take some of the expanded features of such models into account. The first three sections of this chapter go into detail on the structures, relationships, and constraints of your UML data model and their transformation into the relational schema.

The next section of the chapter discusses the concept of data normalization. You really can't talk about relational databases without talking about normalization. If you approach it from the OO perspective, though, you can eliminate much of its complexity and detail. It is still important to understand how your database structure meets the "normal" requirements of the relational world, but it's much easier to get there from an OO data model.

The last section summarizes the sequence of steps you take to transform the OO data model into an SQL-92 schema. It also shows...