Tài liệu Oracle PLSQL Language- P11 docx

Previous: About the Disk Preface Next: Acknowledgments Comments and Questions Please address comments and questions concerning this book to the publisher: O'Reilly & Associates 101 Morris Street Sebastopol, CA 95472 1-800-998-9938 (in the U.S. or Canada) 1-707-829-0515 (international or local) 1-707-829-0104 (FAX) You can also send us messages electronically. See the insert in the book for information about O'Reilly & Associates' online services. For corrections and amplifications for the book, check out http://www.oreilly.com/catalog/oraclep2/. If you have any questions about the disk supplied with this book, contact RevealNet Inc. at http:// www.revealnet.com. Previous: About the Disk Oracle PL/SQL Programming, 2nd Edition Next: Acknowledgments About the Disk Book Index Acknowledgments The Oracle Library Navigation Copyright (c) 2000 O'Reilly & Associates. All rights reserved. Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Previous: Which Platform or Version? Preface Next: Comments and Questions About the Disk The content of the companion Windows disk for this book has been included on this CD, in the / prog2/disk/ directory. This disk contains the Companion Utilities Guide for Oracle PL/SQL Programming, an online tool developed by RevealNet, Inc. that gives you point-and-click access to more than 100 files of source code and documentation that we developed. Many of the code examples are also printed in the book. We've included these to give you a jump start on writing your own PL/ SQL code and to keep you from having to type many pages of PL/SQL statements from printed text. Appendix A, describes how to install the Windows-based interface. You can run the software in any Microsoft Windows environment. If you are working in a non-Windows environment, you can obtain a compressed file containing the utilities on the desk from the RevealNet PL/SQL Pipeline Archives at http://www.revealnet.com/plsql-pipeline. Previous: Which Platform or Version? Oracle PL/SQL Programming, 2nd Edition Next: Comments and Questions Which Platform or Version? Book Index Comments and Questions The Oracle Library Navigation Copyright (c) 2000 O'Reilly & Associates. All rights reserved. Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Previous: Conventions Used in This Book Preface Next: About the Disk Which Platform or Version? In general, all of the discussions and examples in this book apply regardless of the machine and/or operating system you are using. In those few cases where a feature is in any way system-dependent, I note that in the text. There are many versions of PL/SQL, and you may even find that you need to use multiple versions in your development work. Chapter 1, Introduction to PL/SQL describes in detail the many versions of PL/SQL and what you need to know about them; see Section 1.4, "PL/SQL Versions" in Chapter 1 in Chapter 1. Previous: Conventions Used in This Book Oracle PL/SQL Programming, 2nd Edition Next: About the Disk Conventions Used in This Book Book Index About the Disk The Oracle Library Navigation Copyright (c) 2000 O'Reilly & Associates. All rights reserved. Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Previous: Audience Preface Next: Which Platform or Version? Conventions Used in This Book The following conventions are used in this book: Italic is used for file and directory names. Constant width is used for code examples. Constant width bold In some code examples, highlights the statements being discussed. Constant width italic In some code examples, indicates an element (e.g., a filename) that you supply. UPPERCASE In code examples, indicates PL/SQL keywords. lowercase In code examples, indicates user-defined items such as variables, parameters, etc. punctuation In code examples, enter exactly as shown. indentation In code examples, helps to show structure but is not required. In code examples, a double hyphen begins a single-line comment, which extends to the end of a line. /* and */ Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. In code examples, these characters delimit a multiline comment, which can extend from one line to another. . In code examples and related discussions, a dot qualifies a reference by separating an object name from a component name. For example, dot notation is used to select fields in a record and to specify declarations within a package. < > In syntax descriptions, angle brackets enclose the name of a syntactic element. [ ] In syntax descriptions, square brackets enclose optional items. In syntax descriptions, an ellipsis shows that statements or clauses irrelevant to the discussion were left out. Previous: Audience Oracle PL/SQL Programming, 2nd Edition Next: Which Platform or Version? Audience Book Index Which Platform or Version? The Oracle Library Navigation Copyright (c) 2000 O'Reilly & Associates. All rights reserved. Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Previous: Structure of This Book Preface Next: Conventions Used in This Book Audience This book was designed to be used by anyone who needs to develop Oracle-based applications using the PL/SQL programming language. There are a number of distinct audiences: Role How to Use the Book Information systems manager The application development or database administration manager in an Oracle shop needs a thorough grasp of the technology used in the development groups. Familiarity with the technology will help the manager to better understand the challenges faced by the team members and the ability of that team to solve problems. These managers will want to pay particular attention to Part 4, for the big picture of structuring PL/SQL-based applications. One-person information systems shop Oracle licenses are frequently sold into small companies or departments where the supporting information systems organization consists of little more than a single manager and single developer (or perhaps both of those functions rolled into one). These small organizations do not have the time to search through multiple manuals or sets of training notes to find the solution to their problems. This book offers one-stop shopping for these people a consolidated reference and solutions source. Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Database administrator The DBA in the world of Oracle7 needs to build database triggers and stored procedures in order to manage business rules at the RDBMS levels and implement distributed databases. The DBA will use this book to strengthen his or her understanding of how to write efficient RDBMS-level objects. This book will also discuss constructing packages of related objects which will reduce the resources required to maintain these objects. New developer in the Oracle Developer/2000 environment Many developers arrive fresh on the Oracle scene through the use of the new Oracle Developer/2000 tools in the Windows environment. These developers will be comfortable manipulating the various widgets in the GUI world, but will find PL/ SQL to be a strange, new partner for development. This book will quickly bring them up to speed and make them more productive users of Oracle Developer/2000 software. Experienced Oracle developer Many thousands of programmers have spent years writing, debugging, and maintaining programs written in SQL*Forms, SQL*Reportwriter, SQL*Plus, and SQL*Menu. While their PL/SQL skills have progressed to meet the needs of specific applications, most could expand both their PL/SQL knowledge and their awareness of its subtleties. In addition, as developers move into the Oracle Developer/2000 generation, PL/SQL plays a significantly more central role; the developer will have to gain new expertise to meet the demands of this change. Consultant Consultants must offer a high level of service and quality to their customers. This added value is measured in productivity and in the application of skills not currently held by the client. Consultants should find this book an invaluable aid in deepening their understanding of PL/SQL technology. Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Previous: Structure of This Book Oracle PL/SQL Programming, 2nd Edition Next: Conventions Used in This Book Structure of This Book Book Index Conventions Used in This Book The Oracle Library Navigation Copyright (c) 2000 O'Reilly & Associates. All rights reserved. Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Previous: Objectives of This Book Preface Next: Audience Structure of This Book This second edition has changed from the first edition in a number of significant ways. Before listing the individual parts of the book, I want to explain the overall restructuring. About the Second Edition We (the authors and O'Reilly & Associates) are committed to providing comprehensive, useful coverage of the PL/SQL language over the life of this language. The first edition of this book covered most of PL/SQL's features as it existed through PL/SQL Release 2.3. With the release of Oracle8, however, we faced a challenge: how do we fit all the new technologies of PL/SQL8 into Oracle PL/ SQL Programming and fill out coverage of existing elements of PL/SQL without creating a tome so unwieldy that reading the book becomes as much a physical as a mental workout? Furthermore, if we look ahead a few years, we can easily expect that Oracle will continue to roll out expanded functionality in the objects area, as well as providing new and enhanced built-in packages. Given this situation, it quickly became clear to us that it was not practical to offer a single text which covered "all things PL/SQL." Two questions then arose: what do we cut and what do we do with the stuff that we cut? The answers are as follows: ● Move the package examples from the printed text to the disk. The second edition's disk offers a Windows-based interface designed by RevealNet, Inc. (http://www.revealnet.com) allowing you rapid access to the many utilities and samples. Now, instead of having to look through a directory listing and then using an editor to view those files, you will be able to mouse-click and drill-down your way to the topics in which you are interested. We take advantage of this interface to give you an easy way to examine the many examples of packages I built for the book. ● Remove the chapter on built-in packages and expand it into a complete book. This chapter in the first edition offered lots of good information, but it was not comprehensive and simply couldn't keep growing to absorb all the new technology issuing forth from Oracle headquarters. Moving coverage of built-in packages to its own book will give us room to provide more and better information about this key element of the PL/SQL language. Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Appendix A, What's on the Companion Disk?, of this edition of Oracle PL/SQL Programming will still provide a quick reference to the more common built-in packages. About the Contents The second edition of Oracle PL/SQL Programming is divided into seven parts: Part 1, Programming in PL/SQL Chapters 1 through 3 explain what it means to program in PL/SQL and in Oracle-based applications in general. This part of the book introduces you to the main features of the PL/ SQL language and gives you some general advice on programming habits and effective coding style. Part 2, PL/SQL Language Elements Chapters 4 through 10 describe the basic PL/SQL programming components variables, cursors, conditional and sequential control statements, loops, exception handlers, PL/SQL records, and PL/SQL tables. These chapters contain numerous examples, along with tips on how, when, and where to apply these programming constructs most effectively. When you complete this section of the book you will know how to apply all the constructs of the PL/SQL language. You will also be able to examine the complex requirements in your own applications and use the different parts of PL/SQL to implement those requirements. Part 3, Built-In Functions Chapters 11 through 14 present the many built-in (predefined) PL/SQL functions and procedures, which you can put to use immediately in your applications. One of the key barometers of your success with PL/SQL will be the extent to which you know how to leverage all of the capabilities that Oracle Corporation provides. (You don't want to have to reinvent the wheel when so many functions and procedures are provided for you.) Appendix C, Built-In Packages supplements Part 3 by summarizing the syntax of Oracle's built-in packages. Part 4, Modular Code Chapters 15 through 17 take you past the individual components of the PL/SQL language to explore modular construction in PL/SQL. You will learn how to build procedures, functions, and packages; more than that, you will learn how to build them correctly. More than with any other aspect of code, the way you design your modules has an enormous impact on your applications' development time, reusability, and maintainability. Part 5, New PL/SQL8 Features Chapters 18 through 21 contain the main discussion of the new features of Oracle8 in particular, object types, new types of collections (nested tables and VARRAYs), object views, and external procedures. Although we describe Oracle8 enhancements as appropriate in other sections of the book, we localize the major discussion here. Doing so allows developers new Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. [...]... Language Support in Oracle This book does not offer comprehensive coverage of Oracle' s National Language Support (NLS) capabilities for developing applications for multiple languages Trusted Oracle Oracle Corporation has developed a special version of its Oracle7 Server for high-security environments This book does not detail the additional datatypes and features available only for Trusted Oracle Please... very few titles in my Oracle collection of more than 70 books that is actually dog-eared from use All of my colleagues already know the book intimately I have known Steven Feuerstein and his work for a long time through my publishing of Oracle technical publications: the NY Oracle Users newsletter in 1989; the Oracle User Resource newsletter from 1990 to 1994; the International Oracle Users Journal... Data Definition Language (DDL) of Oracle' s SQL Application and database tuning I don't cover detailed tuning issues in this book, though the second edition does add a chapter on PL/SQL tuning Oracle Performance Tuning by Peter Corrigan and Mark Gurry (O'Reilly & Associates, Second Edition, 1997) gives you all the information you need about tuning your Oracle applications Oracle tool-specific technologies... provided by Oracle Corporation to build complex systems that manage vast quantities of data At the heart of much of Oracle' s software is PL/SQL a programming language that provides procedural extensions to the SQL relational database language and an ever-growing range of Oracle development tools PL/SQL figures prominently as an enabling technology in almost every new product released by Oracle Corporation... q q Implementing crucial business rules in the Oracle Server with PL/SQL-based stored procedures and database triggers Enhancing powerful and easy-to-use GUI interfaces of products like Oracle Developer/2000 with detailed, programmatic control Employing object-oriented design principles in Oracle- based applications Linking a World Wide Web page to an Oracle database Perhaps most importantly, PL/SQL... thousands of users on the Internet Oracle is even promising that you will be able to execute Java in the database server itself and write stored procedures in Java rather than PL/SQL So why aren't we rushing off to learn Java? Because even with all of the hoopla over Java, PL/SQL is still the best way to build programs to access data in Oracle7 and Oracle8 databases After Oracle began using PL/SQL to build... technologies as SQL*Forms and Oracle Forms triggers Similarly, you won't find detailed discussions of repeating frames of Oracle Reports in here Nevertheless, many of the techniques offered in this book certainly do apply to the Oracle Developer/2000 environment Third-party application development software There are many alternatives to using PL/SQL and the tools supplied by Oracle to build your applications... 1990 to 1992; the Proceedings of the East Coast Oracle Developers Conference from 1991 to 1996; and since 1994, Pinnacle Publishing's Oracle Developer Steven has been my most prolific and admired writer for more than seven years Now that Steven (with the able help of Bill Pribyl) has updated the original version of Oracle PL/ SQL Programming, I advise every Oracle developer to replace his or her own well-utilized... "poor man's objects" User-defined datatypes such as objects and nested tables (with the Oracle objects option) PL/SQL is integrated tightly into Oracle' s SQL language: you can execute SQL statements directly from your procedural program Conversely, you can also call PL/SQL functions from within a SQL statement Oracle developers who want to be successful in the 1990s and beyond must learn to use PL/SQL... PL/SQL logic With these new improvements, PL/SQL8 assumes even more importance as the principal data access language for Oracle8 Oracle has been methodically enhancing the capabilities of PL/SQL to make it the language of choice for developing distributed computing environments When Oracle finally delivers client-side PL/SQL with the full characteristics of server-side code (effectively turning all clients . of Oracle technical publications: the NY Oracle Users newsletter in 1989; the Oracle User Resource newsletter from 1990 to 1994; the International Oracle. applications for multiple languages. ● Trusted Oracle. Oracle Corporation has developed a special version of its Oracle7 Server for high-security environments.