by Michael Rosenblum and Dr. Paul Dorsey Oracle ® PL/SQL FOR DUMmIES ‰ 01_599577 ffirs.qxp 5/1/06 12:08 PM Page i 01_599577 ffirs.qxp 5/1/06 12:08 PM Page iv by Michael Rosenblum and Dr. Paul Dorsey Oracle ® PL/SQL FOR DUMmIES ‰ 01_599577 ffirs.qxp 5/1/06 12:08 PM Page i Oracle ® PL/SQL For Dummies ® Published by Wiley Publishing, Inc. 111 River Street Hoboken, NJ 07030-5774 www.wiley.com Copyright © 2006 by Wiley Publishing, Inc., Indianapolis, Indiana Published by Wiley Publishing, Inc., Indianapolis, Indiana Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permit- ted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. 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Library of Congress Control Number: 2006922426 ISBN-13: 978-0-7645-9957-6 ISBN-10: 0-7645-9957-7 Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 1O/RX/QV/QW/IN 01_599577 ffirs.qxp 5/1/06 12:08 PM Page ii About the Authors Michael Rosenblum is originally from Kremenchuk, Ukraine. In 2000, he moved to the United States, where he lives with his family in Edison, New Jersey. He works as a Development DBA at Dulcian, Inc. Michael is responsible for system tuning and application architecture. He also supports Dulcian developers by writing complex PL/SQL routines and researching new features. He is a frequent presenter at various regional and national Oracle user group confer- ences. In his native Ukraine, he received the scholarship of the President of Ukraine, a Masters Degree in Information Systems, and a Diploma with Honors from the Kiev National University of Economics, Ukraine. Dr. Paul Dorsey is the founder and President of Dulcian, Inc. (www.dulcian. com), an Oracle consulting firm that specializes in business rules-based Oracle Client-Server and Web custom application development. He is the chief architect of Dulcian’s Business Rules Information Manager (BRIM ® ) tool. Paul is the co-author of seven Oracle Press books that have been translated into nine languages: Oracle JDeveloper 10g Handbook, Oracle9i JDeveloper Handbook, Oracle JDeveloper 3 Handbook, Oracle Designer Handbook (2 editions), Oracle Developer Forms and Reports: Advanced Techniques and Development Standards, Oracle8 Design Using UML Object Modeling. In 2003, he was honored by ODTUG as volunteer of the year, in 2001 by IOUG as vol- unteer of the year and by Oracle as one of the six initial honorary Oracle 9i Certified Masters. Paul is an Oracle Fusion Middleware Regional Director. He is the President of the New York Oracle Users’ Group and a Contributing Editor of the International Oracle User Group’s SELECT Journal. He is also the founder and chairperson of the ODTUG Business Rules Symposium (now called Best Practices Symposium), currently in its sixth year, and the J2EE SIG. Dedications Dedicated to the memory of my grandfather, Vladimir Zaguskin, who was always able to give me a simple explanation of not-so-simple things. — Michael Rosenblum, Edison, NJ, 2006 Dedicated to Dr. Robert Stafford Sterling (my mentor in graduate school and no dummy) and to his namesake Robert Stefan Dorsey (born December 2005, who I hope will also not be a dummy). — Dr. Paul Dorsey, Colonia, NJ, 2006 01_599577 ffirs.qxp 5/1/06 12:08 PM Page iii 01_599577 ffirs.qxp 5/1/06 12:08 PM Page iv Authors’ Acknowledgments Michael Rosenblum: I would like to thank my co-author, Dr. Paul Dorsey (a well-known guru in the Oracle world), for inviting me to take part in writing this book and for all his patience working with me for the last five years. Also, I would like to acknowledge the efforts of our project manager, Caryl Lee Fisher. She not only kept the lazy authors on track, but even managed to convert my not-exactly-native English into something people could read. Of course, the book in the form you are reading it would not have been possible without our wonderful technical editor Leslie Tierstein (you can’t imagine the number of small “bugs” she discovered in the original drafts). And, last but not least, love and special thanks to my wife Dora for withstanding the added pressure on her while I was writing this book. Dr. Paul Dorsey: I would first like to acknowledge my co-author Michael (“Misha”) Rosenblum. It is a joy to work with someone possessing such drive and intellect. His unwillingness to be sloppy in his code and thinking have given not only this book, but all his work, an aspect of excellence all too unusual in this industry. I would also like to thank Caryl Lee Fisher (our unac- knowledged “co-author”). Caryl Lee kept Misha and me on track and helped wordsmith the entire manuscript. This is my eighth such collaboration involving Caryl Lee, and I can safely say that I am not sure whether I ever would have published even my first book without her assistance. She acted as the intermediary between the excellent editors at Wiley and the authors, thereby averting virtually certain bloodshed. She helped to foster the illusion that we are very easy authors to work with. Leslie Tierstein provided her always impeccable technical edits. I have worked with her on a number of projects, and she provides many valuable contributions to the finished prod- uct. A special thank you goes to my lovely wife Ileana. She not only endured all my time away from home (for the 3 months preceding and following my son’s birth) working on this book, but she also provided serious technical assistance, since she is a first-rate developer in her own right. Both authors would like to thank their colleagues Mark Hernandez, Marc Bacchus, John Rydzy, and Stephen Germany for their help in reviewing the code samples and text for accuracy. The authors would also like to thank the Wiley team of Rebecca Huehls, Virginia Sanders, Tiffany Ma, and Terri Varveris for their help with this project. 01_599577 ffirs.qxp 5/1/06 12:08 PM Page v Publisher’s Acknowledgments We’re proud of this book; please send us your comments through our online registration form located at www.dummies.com/register/ . Some of the people who helped bring this book to market include the following: Acquisitions, Editorial, and Media Development Project Editor: Rebecca Huehls Acquisitions Editors: Tiffany Ma, Terri Varveris Copy Editor: Virginia Sanders Technical Editor: Leslie Tierstein Editorial Manager: Leah P. Cameron Media Development Manager: Laura VanWinkle Editorial Assistant: Amanda Foxworth Cartoons: Rich Tennant ( www.the5thwave.com ) Composition Services Project Coordinator: Patrick Redmond Layout and Graphics: Claudia Bell, Carl Byers, Denny Hager, Alicia B. South Proofreaders: Dwight Ramsey, Techbooks Indexer: Techbooks Publishing and Editorial for Technology Dummies Richard Swadley, Vice President and Executive Group Publisher Andy Cummings, Vice President and Publisher Mary Bednarek, Executive Acquisitions Director Mary C. Corder, Editorial Director Publishing for Consumer Dummies Diane Graves Steele, Vice President and Publisher Joyce Pepple, Acquisitions Director Composition Services Gerry Fahey, Vice President of Production Services Debbie Stailey, Director of Composition Services 01_599577 ffirs.qxp 5/1/06 12:08 PM Page vi Contents at a Glance Introduction .1 Part I: Basic PL/SQL Concepts .7 Chapter 1: PL/SQL and Your Database 9 Chapter 2: The PL/SQL Environment .23 Part II: Getting Started with PL/SQL 39 Chapter 3: Laying the Groundwork: PL/SQL Fundamentals .41 Chapter 4: Controlling Program Flow 85 Chapter 5: Handling Exceptions .105 Chapter 6: PL/SQL and SQL Working Together .127 Part III: Standards and Structures .163 Chapter 7: Putting Your Code in the Right Place 165 Chapter 8: Creating Naming Standards .187 Chapter 9: Creating Coding Standards 201 Part IV: PL/SQL Data Manipulations 219 Chapter 10: Basic Datatypes .221 Chapter 11: Advanced Datatypes .253 Part V: Taking PL/SQL to the Next Level .289 Chapter 12: Transaction Control 291 Chapter 13: Dynamic SQL and PL/SQL 313 Chapter 14: PL/SQL Best Practices .335 Part VI: The Part of Tens .355 Chapter 15: Ten PL/SQL Tips 357 Chapter 16: Ten Common Mistakes to Avoid in PL/SQL 377 Index .397 02_599577 ftoc.qxp 5/1/06 12:09 PM Page vii [...]... source of the information and test any code carefully before deploying it The following are two particularly useful Web sites for obtaining the latest information about PL/SQL: Introduction ߜ Oracle Technology Network (OTN) (www.otn .oracle. com) is Oracle s online resource for all its database and application products See especially the special technology section devoted to PL/SQL (www .oracle com/technology/tech/pl_sql/index.html)... 16 The Scoop on SQL and PL/SQL 16 The purpose of SQL and PL/SQL 17 The difference between SQL and PL/SQL 18 What’s new in Oracle SQL and PL/SQL? 18 What Is PL/SQL Good For? 19 Using database triggers .19 Scripting with speed 20 Keeping code server-side 20 Programming for Oracle Developer 21 Chapter 2: The PL/SQL Environment ... Part V: Taking PL/SQL to the Next Level For those who have some basic experience with PL/SQL, Part V discusses more complex concepts, including database interaction and transaction control in Chapter 12 and using dynamic SQL and PL/SQL in Chapter 13 Chapter 14 lists some PL/SQL coding best practices to follow based on our wide experiences in building working systems 3 4 Oracle PL/SQL For Dummies Part... Feuerstein writes often about PL/SQL His Web site (www stevenfeuerstein.com) is a great resource The many Oracle User Groups can provide lots of helpful information and events for Oracle professionals By attending a user group conference, you can discover more about the Oracle environment ߜ Oracle Development Tools User Group (ODTUG) (www.odtug.com) is the leading Oracle user group for developers It focuses... other PL/SQL developers, and connect with other Oracle professionals That is the best way to keep up with the rapidly changing Oracle environment 5 6 Oracle PL/SQL For Dummies Part I Basic PL/SQL Concepts P In this part art I includes two chapters to get you started with PL/SQL Because you need to understand something about relational databases to be a good PL/SQL programmer, Chapter 1 provides a quick... administrator (DBA), it might be a good additional reference, but you should see Oracle 9i For Dummies (latest version as of this writing), by Carol McCullough-Dieter, published by Wiley, or other books about Oracle 10g for information relevant for DBAs When an author writes a book, he or she must try to imagine who the readers might be For this book, we imagine that you might be an individual who recently graduated... thought PL/SQL developers should know If you practice everything we show you in this book, you’ll be on your way to becoming an excellent developer To help you practice, we’ve posted the code examples that appear in this book on our Web site, www.dulcian.com (click the publications link), or at www .dummies. com/go /oracle_ pl_sql 2 Oracle PL/SQL For Dummies Foolish Assumptions This book is written for people... additional helpful information about PL/SQL to expand your knowledge You can’t program successfully in isolation It is very important to be plugged into the broader Oracle community through local user groups, conferences, the Internet, and other PL/SQL programmers Many useful sources of information about PL/SQL and the Oracle Environment are on the Internet Keep in mind that not all information and code... can use to practice Chapter 1 PL/SQL and Your Database In This Chapter ᮣ Getting to know relational databases ᮣ Understanding database terminology ᮣ Finding out about Oracle ᮣ Using SQL and PL/SQL ᮣ Discovering what PL/SQL is good for P L/SQL is an extension to the industry-standard SQL language Oracle Corporation developed PL/SQL and released the first version in 1991 PL/SQL is an easy-to-use procedural... quickly .350 Test first .351 xv xvi Oracle PL/SQL For Dummies Keeping Up-to-Date with Oracle 352 Conventional wisdom isn’t always right 352 Buy books 353 Go to conferences .353 Join your local Oracle user group 354 Use online resources 354 Part VI: The Part of Tens 355 Chapter 15: Ten PL/SQL Tips 357 . Rosenblum and Dr. Paul Dorsey Oracle ® PL/SQL FOR DUMmIES ‰ 01_599577 ffirs.qxp 5/1/06 12:08 PM Page i Oracle ® PL/SQL For Dummies ® Published by Wiley. Publishing logo, For Dummies, the Dummies Man logo, A Reference for the Rest of Us!, The Dummies Way, Dummies Daily, The Fun and Easy Way, Dummies. com, and