Khi chúng ta không có một điều kiện để xác định các thành viên trong một lớp con, lớp con được gọi là người dùng định nghĩa. Thành viên trong một lớp con được xác định bởi người sử dụng cơ sở dữ liệu khi họ áp dụng các hoạt động để thêm một thực thể phân lớp, do đó, thành viên được quy định cụ thể riêng cho eachentity bởi người sử dụng, | FUNDAMENTALS OF 0ATABASE Systems FUNDAMENTALS OF .Database Systems Ramez Elmasri Department of Computer Science Engineering University of Texas at Arlington Shamkant B. Navathe College of Computing Georgia Institute of Technology PEARSON Addison Wesley Boston San Francisco New York London Toronto Sydney Tokyo Singapore Madrid Mexico City Munich Paris Cape Town Hong Kong Montreal Sponsoring Editor Maite Suarez-Rivas Project Editor Katherine Harutunian Senior Production Supervisor Juliet Silver Production Services Argosy Publishing Cover Designer Beth Anderson Marketing Manager Nathan Schultz Senior Marketing Coordinator Lesly Hershman Print Buyer Caroline Fell Cover image 2003 Digital Vision Access the latest information about Addison-Wesley titles from our World Wide Web site http cs Figure is a logical data model diagram definition in Rational Rose . Figure is a graphical data model diagram in Rational Rose . Figure is the company database class diagram drawn in Rational Rose . IBM has acquired Rational Rose . Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book and Addison-Wesley was aware of a trademark claim the designations have been printed in initial caps or all caps. The programs and applications presented in this book have been included for their instructional value. They have been tested with care but are not guaranteed for any particular purpose. The publisher does not offer any warranties or representations nor does it accept any liabilities with respect to the programs or applications. Library of Congress Cataloging-in-Publication Data Elmasri Ramez. Fundamentals of database systems Ramez Elmasri Shamkant B. Navathe. 4th ed. p. cm. Includes bibliographical references and index. ISBN 0-321-12226-7 1. Database management. I. Navathe Sham. II. Title. 2003 2003057734 ISBN 0-321-12226-7 For .
