Tài liệu về học lập trình web bằng ngôn ngữ PHP cho tất cả mọi người.
MySQL/PHP Database Applications MySQL/PHP Database Applications Jay Greenspan and Brad Bulger M&T Books An imprint of IDGBooks Worldwide, Inc. Foster City, CA ● Chicago, IL ● Indianapolis, IN ● New York, NY LIMIT OF LIABILITY/DISCLAIMER OF WARRANTY: THE PUBLISHER AND AUTHOR HAVE USED THEIR BEST EFFORTS IN PREPARING THIS BOOK. THE PUBLISHER AND AUTHOR MAKE NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS BOOK AND SPECIFICALLY DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. THERE ARE NO WARRANTIES WHICH EXTEND BEYOND THE DESCRIPTIONS CONTAINED IN THIS PARAGRAPH. NO WARRANTY MAY BE CREATED OR EXTENDED BY SALES REPRESENTATIVES OR WRITTEN SALES MATERIALS. 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About the Authors Jay Greenspan made his living as a technical consultant and editor before finding his way into Wired Digital’s Webmonkey. There he learned everything he knows about Web technology and gained an appreciation for electronic music, the color orange, and a “cute top.” He now makes his living as a writer and consultant. He will neither confirm nor deny the rumors that he once worked for a prime-time game show. Brad Bulger can remember when computers were as big as refrigerators and old- timers would come into the machine room and call them “mini.” He learned more than anyone really should about database systems by working for Relational Technology nee Ingres nee CA for many years. After an interregnum, he got a job with Wired. He would still like to know when the future is going to get here, but has a sneaking suspicion he already knows. Credits ACQUISITIONS EDITOR Debra Williams Cauley PROJECT EDITOR Neil Romanosky TECHNICAL EDITORS Richard Lynch Michael Widenius COPY EDITOR S. B. Kleinman PROJECT COORDINATORS Louigene A. Santos Danette Nurse GRAPHICS AND PRODUCTION SPECIALISTS Robert Bilhmayer Rolly Delrosario Jude Levinson Michael Lewis Ramses Ramirez Victor Pérez-Varela QUALITY CONTROL TECHNICIAN Dina F Quan PERMISSIONS EDITOR Laura Moss MEDIA DEVELOPMENT SPECIALIST Angela Denny MEDIA DEVELOPMENT COORDINATOR Marisa Pearman BOOK DESIGNER Jim Donohue ILLUSTRATORS Gabriele McCann Ronald Terry PROOFREADING AND INDEXING York Production Services COVER IMAGE © Noma/Images.com In memory of Dr. Jonathan B. Postel Preface Welcome. If you are thumbing through these pages, you’re probably considering writing Web-based applications with PHP and MySQL. If you decide to go with these tools, you’ll be in excellent company. Thousands of developers —from total newbies to programmers with years of experience —are turning to PHP and MySQL for their Web-based projects; and for good reason. Both PHP and MySQL are easy to use, fast, free, and powerful. If you want to get a dynamic Web site up quickly, there are no better choices. The PHP scripting lan- guage was built for the Web. All the tasks common to Web development can be accomplished in PHP with an absolute minimum of effort. Similarly, MySQL excels at tasks common to dynamic Web sites. Whether you’re creating a content-management system or an e-commerce application, MySQL is a great choice for your data storage. Is This Book for You? There are quite a few books that deal with PHP and a few that cover MySQL. We’ve read some of these and found a few to be quite helpful. If you’re looking for a book that deals with gory details of either of these packages, you should probably look elsewhere. The focus of this book is applications development. We are concerned with what it takes to get data-driven Web sites up and running in an organized and efficient way. The book does not go into arcane detail of every aspect of either of these tools. For example, in this book, you will not find a discussion of PHP’s LDAP functions or MySQL’s C application program interface (API). Instead, we will focus on the pieces of both packages that affect one another. We hope that by the time you’re done with this book you’ll know what it takes to get an application up and running using PHP and MySQL. How This Book Is Organized We have organized the book into four parts. Part I: Using MySQL Before you code any PHP scripts, you will need to know how to design a database, create tables in your database, and get the information you want from the database. Part I of this book will show you about all you need to know to work with MySQL. ix Part II: Using PHP As an applications developer, the bulk of your time will be spent writing scripts that access the database and present HTML to a user’s browser. Part II will start by showing you the basics of the PHP scripting language, covering how PHP works with variables, conditions, and control structures. Part II will also cover many of PHP’s functions and discuss techniques for writing clean, manageable code. Part III: Simple Applications In this part, we present two of the seven applications in this book: a guestbook and a survey. Here you will see the lessons from Parts I and II put into practice as we build working applications. Part IV: Not So Simple Applications Here the applications will be more complex, as we present applications commonly used on the Web. You will see how you can design a content management system, a discussion board, a shopping cart, and other useful applications. Along the way, we will show some tips and techniques that should be helpful as you write your applications. Part V: Appendixes The appendixes cover several topics of interest to the MySQL/PHP developer. In the appendixes, you will find installation and configuration instructions, quick refer- ence guides to PHP and MySQL functions, a regular expressions overview, and guides to MySQL administration. In addition, there are a few helpful resources, snippets of code, and instructions on using the CD-ROM. Tell Us What You Think Both the publisher and authors of this book hope you find it a valuable resource. Please feel free to register this book at the IDG Books Web site (http://www. idgbooks.com) and give us your feedback. Also check in at the site we’ve dedicated to this book, http://www.mysqlphpapps.com/, where you will be able to contact the authors and find updates to the applications created for this book. x Preface Acknowledgments This book would never have happened if not for the efforts of Debra Williams Cauley. I thank her for her patience and persistence. The efforts and talents of Neil Romanosky, S. B. Kleinman, and many others at IDG Books have made this book more lucid and attractive than we could have hoped. Richard Lynch’s exacting eye and technical acumen kept our code clean, fast, and readable. Any book on open-source software owes debt to those who have created these great tools. So I thank everyone involved with PHP and MySQL, from the core developers to those who contribute to the documentation. Special thanks to Michael (Monty) Widenius, MySQL’s lead developer. He has not only created a ter- rific relational database, but has offered his advice and expertise to the authors of this book. xi [...]... 405 Brief Guide to PHP/ MySQL Installation and Configuration 413 MySQL Utilities 423 MySQL User Administration 439 PHP Function Reference 447 Regular Expressions Overview 507 Helpful User- Defined Functions 517 PHP and MySQL Resources 543 MySQL Function Reference... Guide to PHP/ MySQL Installation and Configuration 413 MySQL Utilities 423 MySQL User Administration 439 PHP Function Reference 447 Regular Expressions Overview 507 Helpful User- Defined Functions 517 PHP and MySQL Resources 543 MySQL Function... Introduction path to mysql.exe, and execute it Then, at the prompt, create a new database When you’re done, you should have something that looks very much like this: [jay@mybox jay]$ mysql Welcome to the MySQL monitor Commands end with ; or \g Your MySQL connection id is 716 to server version: 3.22.27-log Type ‘help’ for help mysql> create database guestbook; Query OK, 1 row affected (0.00 sec) mysql> Now, within... ‘$comments’)” ; mysql_query($query) or die (mysql_error()); ?> Thanks!! View My Guest Book!!! < ?php } else { include(“sign .php ); } ?> If the form, which is in sign .php, hasn’t been submitted, it is included and therefore will show the same form You may notice that this page is submitted to itself Introduction The first time the create_entry .php page is called,... developing with PHP and MySQL Both products run on Windows 95/98 and Windows NT/2000 But in the real world, almost all PHP/ MySQL applications are running off of some version of Unix, whether it be Linux, BSD, Irix, Solaris, HP-UX, or one of the other flavors For that reason, the applications in this book will work with Unix If you need to run these on Windows, minor alterations to the PHP scripts may... server You will probably be using Apache, whether you are using Windows or Unix You will need to install Apache so that it can access the PHP language In addition, you will need to have MySQL installed And PHP will have to be able to recognize MySQL Apache, MySQL, and PHP are provided on the accompanying CD, and installation instructions are provided in Appendix B You may want to install these packages... for many MySQL is free You can install and use it and pay nothing in the process xxix xxx Introduction IT’S QUICK AND POWERFUL MySQL may not have every bell and whistle available for a relational database, but for most users there is plenty If you are serving out Web content or creating a moderately sized commerce site, MySQL has all the power you need For small-to-medium-sized databases, MySQL will... also created in the MySQL monitor The command to create the table isn’t very complex You basically need to let MySQL know what kind of information to expect, whether numbers or stings, and whether or not any of the information can be omitted (or NULL) The basic command is create table; it will look about like this when you make the table: mysql> use guestbook Database changed mysql> create table guestbook... CONNECTING TO THE DATABASE While you’re installing PHP, you should let it know that you plan on using MySQL with it If you don’t do this, what we will discuss now won’t work Even if PHP is aware that you’re using MySQL, in your specific scripts you must identify the exact database you need access to In this case, that will be the guestbook database you just created mysql_connect(“localhost”, “nobody”,”password”)... being here Web applications are the present and the future No matter your background, whether it be Visual Basic or COBOL, or maybe you know just some HTML and JavaScript, your résumé is only going to improve with some Web applications development experience We don’t think there’s a better combination of tools to have under your belt than PHP and MySQL The numbers bear us out PHP and MySQL are becoming