Projeto e implementação de esquemas externos baseados no modelo de entidades e relacionamentos.

Abstract

This work aims to provide the most diverse database managers with a standardized Conceptual Model, in which each user, or group of users, has access to only one part of the database (External Scheme), whose reach depends on the permissions. given. Therefore, any data manipulation operation (consultation and maintenance) is performed according to the respective definition of the external schema. In this sense, we present here a data modeling proposal for the conceptual level and for the external level, as well as describe the data definition and manipulation languages used in our model and the implemented implementations.