1. Presentation

Knowledge of the principles involved in transposing the object model into the relational model commonly used both statically (definition of relational tables) and dynamically (data access services) is essential, both for implementing specific transposition services, and for making informed use of an existing transposition tool.

To present a number of these rules, we'll use the conceptual diagram in figure 1 , represented using UML (Unified Modeling Language) formalism and graphics.

This example models a customer who may be either an individual or an institution. A customer owns a set of contracts (current account, securities account, etc.). A natural...