Beginning PHP and Oracle

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Beginning PHP and Oracle

From Novice to Professional

■ ■ ■

W. Jason Gilmore and Bob Bryla

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All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher.

ISBN-13 (pbk): 978-1-59059-770-5 ISBN-10 (pbk): 1-59059-770-2

Printed and bound in the United States of America 9 8 7 6 5 4 3 2 1

Trademarked names may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, we use the names only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark.

Lead Editor: Jonathan Gennick Technical Reviewer: Matt Wade

Editorial Board: Steve Anglin, Ewan Buckingham, Gary Cornell, Jonathan Gennick, Jason Gilmore, Jonathan Hassell, Chris Mills, Matthew Moodie, Jeffrey Pepper, Ben Renow-Clarke, Dominic Shakeshaft, Matt Wade, Tom Welsh

Project Manager: Kylie Johnston

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—W. Jason Gilmore

To CRB and ESB, even with my long hours we had a great summer of fun!

—Bob Bryla

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v

About the Authors . . . xxvii

About the Technical Reviewer . . . xxix

Acknowledgments . . . xxxi

Introduction . . . .xxxiii

■ ^{CHAPTER 1} Introducing PHP

. . . 1

■ ^{CHAPTER 2} Configuring Your Environment

. . . 9

■ ^{CHAPTER 3} ^{PHP Basics}

. . . 39

■ ^{CHAPTER 4} ^Functions

. . . 81

■ ^{CHAPTER 5} ^Arrays

. . . 91

■ ^{CHAPTER 6} Object-Oriented PHP

. . . 117

■ ^{CHAPTER 7} Advanced OOP Features

. . . 139

■ ^{CHAPTER 8} Error and Exception Handling

. . . 151

■ ^{CHAPTER 9} Strings and Regular Expressions

. . . 163

■ ^{CHAPTER 10} Working with the File and Operating System

. . . 195

■ ^{CHAPTER 11} ^PEAR

. . . 219

■ ^{CHAPTER 12} Date and Time

. . . 229

■ ^{CHAPTER 13} ^Forms

. . . 249

■ ^{CHAPTER 14} Authentication

. . . 261

■ ^{CHAPTER 15} Handling File Uploads

. . . 277

■ ^{CHAPTER 16} ^Networking

. . . 287

■ ^{CHAPTER 17} PHP and LDAP

. . . 305

■ ^{CHAPTER 18} Session Handlers

. . . 319

■ ^{CHAPTER 19} Templating with Smarty

. . . 339

■ ^{CHAPTER 20} Web Services

. . . 361

■ ^{CHAPTER 21} Secure PHP Programming

. . . 387

■ ^{CHAPTER 22} ^SQLite

. . . 407

■ ^{CHAPTER 23} Introducing PDO

. . . 425

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vi

■

■ ^{CHAPTER 26} Introducing Oracle

. . . 463

■ ^{CHAPTER 27} Installing and Configuring Oracle Database XE

. . . 469

■ ^{CHAPTER 28} Oracle Database XE Administration

. . . 481

■ ^{CHAPTER 29} Interacting with Oracle Database XE

. . . 501

■ ^{CHAPTER 30} From Databases to Datatypes

. . . 513

■ ^{CHAPTER 31} Securing Oracle Database XE

. . . 535

■ ^{CHAPTER 32} PHP’s Oracle Functionality

. . . 565

■ ^{CHAPTER 33} Transactions

. . . 591

■ ^{CHAPTER 34} Using HTML_Table with Advanced Queries

. . . 601

■ ^{CHAPTER 35} Using Views

. . . 621

■ ^{CHAPTER 36} Oracle PL/SQL Subprograms

. . . 633

■ ^{CHAPTER 37} Oracle Triggers

. . . 649

■ ^{CHAPTER 38} Indexes and Optimizing Techniques

. . . 661

■ ^{CHAPTER 39} Importing and Exporting Data

. . . 675

■ ^{CHAPTER 40} Backup and Recovery

. . . 687

■ ^INDEX

. . . 697

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vii

About the Authors . . . xxvii

. . . 15

Configuring FastCGI to Manage PHP Processes

. . . 16

Testing Your Installation

. . . 17

Configuring PHP

. . . 19

Configuring PHP at Build Time on Linux

. . . 19

Customizing the Windows Build

Variables

. . . 52

Variable Declaration

. . . 52

Variable Scope

. . . 54

PHP’s Superglobal Variables

. . . 56

Variable Variables

. . . 60

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Constants

. . . 61

Expressions

. . . 61

Operands

. . . 62

Operators

. . . 62

String Interpolation

. . . 68

Double Quotes

. . . 68

Single Quotes

. . . 69

Heredoc

. . . 69

Control Structures

. . . 70

Conditional Statements

. . . 70

Looping Statements

. . . 72

File Inclusion Statements

. . . 77

Summary

. . . 80

■ ^{CHAPTER 4} Functions

. . . 81

Invoking a Function

. . . 81

Creating a Function

. . . 82

Passing Arguments by Value

. . . 82

Passing Arguments by Reference

. . . 83

Default Argument Values

. . . 84

Returning Values from a Function

. . . 85

Recursive Functions

. . . 86

Function Libraries

. . . 89

Summary

. . . 90

■ ^{CHAPTER 5} Arrays

. . . 91

What Is an Array?

. . . 91

Creating an Array

. . . 92

Creating Arrays with array()

. . . 93

Extracting Arrays with list()

. . . 94

Populating Arrays with a Predefined Value Range

. . . 94

Testing for an Array

. . . 95

Adding and Removing Array Elements

. . . 96

Adding a Value to the Front of an Array

. . . 96

Adding a Value onto the End of an Array

. . . 96

Removing a Value from the Front of an Array

. . . 97

Removing a Value from the End of an Array

. . . 97

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Locating Array Elements

. . . 97

Searching an Array

. . . 97

Retrieving Array Keys

. . . 98

Retrieving Array Values

. . . 99

Traversing Arrays

. . . 99

Retrieving the Current Array Key

. . . 99

Retrieving the Current Array Value

. . . 100

Retrieving the Current Array Key and Value

. . . 100

Moving the Array Pointer

. . . 100

Passing Array Values to a Function

. . . 101

Determining Array Size and Uniqueness

. . . 102

Determining the Size of an Array

. . . 102

Counting Array Value Frequency

. . . 103

Determining Unique Array Values

. . . 103

Sorting Arrays

. . . 104

Reversing Array Element Order

. . . 104

Flipping Array Keys and Values

. . . 104

Sorting an Array

. . . 105

Merging, Slicing, Splicing, and Dissecting Arrays

. . . 109

Merging Arrays

. . . 109

Recursively Appending Arrays

. . . 110

Combining Two Arrays

. . . 110

Slicing an Array

. . . 111

Splicing an Array

. . . 112

Calculating an Array Intersection

. . . 112

Calculating Associative Array Intersections

. . . 113

Calculating Array Differences

. . . 113

Calculating Associative Array Differences

. . . 114

Other Useful Array Functions

. . . 114

Returning a Random Set of Keys

. . . 114

Shuffling Array Elements

. . . 115

Summary

. . . 116

■ ^{CHAPTER 6} Object-Oriented PHP

. . . 117

The Benefits of OOP

. . . 117

Encapsulation

. . . 118

Inheritance

. . . 118

Polymorphism

. . . 118

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Key OOP Concepts

. . . 119

Classes

. . . 119

Objects

. . . 120

Fields

. . . 120

Properties

. . . 123

Constants

. . . 125

Methods

. . . 126

Constructors and Destructors

. . . 129

Constructors

. . . 130

Destructors

. . . 132

Static Class Members

. . . 133

The instanceof Keyword

. . . 134

Helper Functions

. . . 135

Autoloading Objects

. . . 136

Summary

. . . 137

■ ^{CHAPTER 7} Advanced OOP Features

. . . 139

Advanced OOP Features Not Supported by PHP

. . . 139

Object Cloning

. . . 140

Cloning Example

. . . 140

The __clone() Method

. . . 141

Inheritance

. . . 142

Class Inheritance

. . . 143

Inheritance and Constructors

. . . 145

Interfaces

. . . 146

Implementing a Single Interface

. . . 147

Implementing Multiple Interfaces

. . . 148

Abstract Classes

. . . 149

Summary

. . . 150

■ ^{CHAPTER 8} Error and Exception Handling

. . . 151

Configuration Directives

. . . 151

Error Logging

. . . 154

Exception Handling

. . . 156

Why Exception Handling Is Handy

. . . 157

PHP’s Exception-Handling Implementation

. . . 158

Summary

. . . 162

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■ ^{CHAPTER 9} Strings and Regular Expressions

. . . 163

Regular Expressions

. . . 163

Regular Expression Syntax (POSIX)

. . . 164

PHP’s Regular Expression Functions (POSIX Extended)

. . . 166

Regular Expression Syntax (Perl)

. . . 169

Other String-Specific Functions

. . . 175

Determining the Length of a String

. . . 175

Comparing Two Strings

. . . 176

Manipulating String Case

. . . 177

Converting Strings to and from HTML

. . . 179

Alternatives for Regular Expression Functions

. . . 183

Padding and Stripping a String

. . . 190

Counting Characters and Words

. . . 191

Taking Advantage of PEAR: Validate_US

. . . 193

Installing Validate_US

. . . 193

Using Validate_US

. . . 194

Summary

. . . 194

■ ^{CHAPTER 10} Working with the File and Operating System

. . . 195

Learning About Files and Directories

. . . 195

Parsing Directory Paths

. . . 196

Calculating File, Directory, and Disk Sizes

. . . 197

Determining Access and Modification Times

. . . 200

Working with Files

. . . 201

The Concept of a Resource

. . . 201

Recognizing Newline Characters

. . . 202

Recognizing the End-of-File Character

. . . 202

Opening and Closing a File

. . . 202

Reading from a File

. . . 204

Writing a String to a File

. . . 209

Moving the File Pointer

. . . 210

Reading Directory Contents

. . . 210

Executing Shell Commands

. . . 212

System-Level Program Execution

. . . 213

Sanitizing the Input

. . . 213

PHP’s Program Execution Functions

. . . 214

Summary

. . . 217

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■ ^{CHAPTER 11} PEAR

. . . 219

Popular PEAR Packages

. . . 219

Preinstalled Packages

. . . 219

Installer-Suggested Packages

. . . 220

The Power of PEAR: Converting Numeral Formats

. . . 221

Installing and Updating PEAR

. . . 222

Installing PEAR

. . . 222

PEAR and Hosting Companies

. . . 223

Updating PEAR

. . . 223

Using the PEAR Package Manager

. . . 223

Viewing an Installed PEAR Package

. . . 224

Learning More About an Installed PEAR Package

. . . 224

Installing a PEAR Package

. . . 225

Including a Package Within Your Scripts

. . . 226

Upgrading Packages

. . . 227

Uninstalling a Package

. . . 228

Downgrading a Package

. . . 228

Summary

. . . 228

■ ^{CHAPTER 12} Date and Time

. . . 229

The Unix Timestamp

. . . 229

PHP’s Date and Time Library

. . . 230

Validating Dates

. . . 230

Formatting Dates and Times

. . . 231

Converting a Timestamp to User-Friendly Values

. . . 234

Working with Timestamps

. . . 235

Date Fu

. . . 236

Displaying the Localized Date and Time

. . . 237

Displaying the Web Page’s Most Recent Modification Date

. . . 240

Determining the Number of Days in the Current Month

. . . 240

Determining the Number of Days in Any Given Month

. . . 241

Calculating the Date X Days from the Present Date

. . . 241

Taking Advantage of PEAR: Creating a Calendar

. . . 242

Date and Time Enhancements for PHP 5.1+ Users

. . . 245

Introducing the DateTime Constructor

. . . 245

Formatting Dates

. . . 245

Setting the Date After Instantiation

. . . 245

Setting the Time After Instantiation

. . . 246

Modifying Dates and Times

. . . 246

Summary

. . . 247

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■ ^{CHAPTER 13} Forms

. . . 249

PHP and Web Forms

. . . 249

A Simple Example

. . . 250

Passing Form Data to a Function

. . . 251

Working with Multivalued Form Components

. . . 252

Taking Advantage of PEAR: HTML_QuickForm

. . . 253

Installing HTML_QuickForm

. . . 254

Creating a Simple Form

. . . 254

Using Auto-Completion

. . . 258

Summary

. . . 259

■ ^{CHAPTER 14} Authentication

. . . 261

HTTP Authentication Concepts

. . . 261

PHP Authentication

. . . 262

Authentication Variables

. . . 262

Useful Functions

. . . 263

PHP Authentication Methodologies

. . . 264

Hard-Coded Authentication

. . . 264

File-Based Authentication

. . . 265

Database-Based Authentication

. . . 266

IP-Based Authentication

. . . 268

User Login Administration

. . . 270

Testing Password Guessability with the CrackLib Library

. . . 270

One-Time URLs and Password Recovery

. . . 272

Summary

. . . 275

■ ^{CHAPTER 15} Handling File Uploads

. . . 277

Uploading Files via HTTP

. . . 277

Uploading Files with PHP

. . . 278

PHP’s File Upload/Resource Directives

. . . 278

The $_FILES Array

. . . 279

PHP’s File-Upload Functions

. . . 280

Upload Error Messages

. . . 281

A Simple Example

. . . 282

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Taking Advantage of PEAR: HTTP_Upload

. . . 283

Installing HTTP_Upload

. . . 283

Uploading a File

. . . 283

Learning More About an Uploaded File

. . . 284

Uploading Multiple Files

. . . 285

Summary

. . . 285

■ ^{CHAPTER 16} Networking

. . . 287

DNS, Services, and Servers

. . . 287

DNS

. . . 288

Services

. . . 291

Establishing Socket Connections

. . . 292

Mail

. . . 294

Configuration Directives

. . . 294

Sending E-mail Using a PHP Script

. . . 295

Common Networking Tasks

. . . 299

Pinging a Server

. . . 299

Creating a Port Scanner

. . . 300

Creating a Subnet Converter

. . . 301

Testing User Bandwidth

. . . 302

Summary

. . . 303

■ ^{CHAPTER 17} PHP and LDAP

. . . 305

Using LDAP from PHP

. . . 306

Connecting to an LDAP Server

. . . 306

Retrieving LDAP Data

. . . 309

Counting Retrieved Entries

. . . 312

Sorting LDAP Records

. . . 312

Inserting LDAP Data

. . . 313

Updating LDAP Data

. . . 314

Deleting LDAP Data

. . . 314

Working with the Distinguished Name

. . . 315

Error Handling

. . . 316

Summary

. . . 317

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■ ^{CHAPTER 18} Session Handlers

. . . 319

What Is Session Handling?

. . . 319

Configuration Directives

. . . 321

Managing the Session Storage Media

. . . 321

Setting the Session Files Path

. . . 321

Automatically Enabling Sessions

. . . 322

Setting the Session Name

. . . 322

Choosing Cookies or URL Rewriting

. . . 322

Automating URL Rewriting

. . . 322

Setting the Session Cookie Lifetime

. . . 323

Setting the Session Cookie’s Valid URL Path

. . . 323

Setting Caching Directions for Session-Enabled Pages

. . . 323

Working with Sessions

. . . 324

Starting a Session

. . . 324

Destroying a Session

. . . 325

Setting and Retrieving the Session ID

. . . 325

Creating and Deleting Session Variables

. . . 326

Encoding and Decoding Session Data

. . . 326

Practical Session-Handling Examples

. . . 328

Automatically Logging In Returning Users

. . . 328

Generating a Recently Viewed Document Index

. . . 330

Creating Custom Session Handlers

. . . 332

Tying Custom Session Functions into PHP’s Logic

. . . 333

Custom Oracle-Based Session Handlers

. . . 333

Summary

. . . 337

■ ^{CHAPTER 19} Templating with Smarty

. . . 339

What’s a Templating Engine?

. . . 339

Introducing Smarty

. . . 341

Installing Smarty

. . . 342

Using Smarty

. . . 343

Smarty’s Presentational Logic

. . . 344

Comments

. . . 345

Variable Modifiers

. . . 345

Control Structures

. . . 348

Statements

. . . 352

Creating Configuration Files

. . . 354

config_load

. . . 355

Referencing Configuration Variables

. . . 355

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Using CSS in Conjunction with Smarty

. . . 356

Caching

. . . 357

Working with the Cache Lifetime

. . . 357

Eliminating Processing Overhead with is_cached()

. . . 358

Creating Multiple Caches per Template

. . . 358

Some Final Words About Caching

. . . 359

Summary

. . . 360

■ ^{CHAPTER 20} Web Services

. . . 361

Why Web Services?

. . . 361

Real Simple Syndication

. . . 363

RSS Syntax

. . . 365

MagpieRSS

. . . 366

SimpleXML

. . . 372

Loading XML

. . . 373

Parsing the XML

. . . 374

SOAP

. . . 377

SOAP Messages

. . . 378

PHP’s SOAP Extension

. . . 378

Summary

. . . 385

■ ^{CHAPTER 21} Secure PHP Programming

. . . 387

Configuring PHP Securely

. . . 387

Safe Mode

. . . 387

Other Security-Related Configuration Parameters

. . . 390

Hiding Configuration Details

. . . 391

Hiding Apache

. . . 392

Hiding PHP

. . . 393

Hiding Sensitive Data

. . . 394

Hiding the Document Root

. . . 394

Denying Access to Certain File Extensions

. . . 394

Sanitizing User Data

. . . 395

File Deletion

. . . 395

Cross-Site Scripting

. . . 395

Sanitizing User Input: The Solution

. . . 397

Taking Advantage of PEAR: Validate

. . . 399

Data Encryption

. . . 400

PHP’s Encryption Functions

. . . 401

The MCrypt Package

. . . 403

Summary

. . . 405

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■ ^{CHAPTER 22} SQLite

. . . 407

Introduction to SQLite

. . . 407

Installing SQLite

. . . 407

Using the SQLite Command-Line Interface

. . . 408

PHP’s SQLite Library

. . . 409

sqlite.assoc_case = 0 | 1 | 2

. . . 409

Opening a Connection

. . . 410

Creating a Table in Memory

. . . 411

Closing a Connection

. . . 411

Querying a Database

. . . 412

Parsing Result Sets

. . . 413

Retrieving Result Set Details

. . . 416

Manipulating the Result Set Pointer

. . . 418

Retrieving a Table’s Column Types

. . . 419

Working with Binary Data

. . . 420

Creating and Overriding SQLite Functions

. . . 421

Creating Aggregate Functions

. . . 422

Summary

. . . 423

■ ^{CHAPTER 23} Introducing PDO

. . . 425

Another Database Abstraction Layer?

. . . 426

Using PDO

. . . 427

Installing PDO

. . . 427

PDO’s Database Support

. . . 428

Connecting to a Database Server and Selecting a Database

. . . 428

Handling Errors

. . . 430

Executing Queries

. . . 431

Prepared Statements

. . . 433

Retrieving Data

. . . 436

Setting Bound Columns

. . . 439

Transactions

. . . 440

Summary

. . . 440

■ ^{CHAPTER 24} Building Web Sites for the World

. . . 441

Approaches to Internationalizing and Localizing Applications

. . . 441

Translating Web Sites with Gettext

. . . 442

Localizing Dates, Numbers, and Times

. . . 446

Summary

. . . 447

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■ ^{CHAPTER 25} MVC and the Zend Framework

. . . 449

Introducing MVC

. . . 449

PHP’s Framework Solutions

. . . 451

The CakePHP Framework

. . . 452

The Solar Framework

. . . 452

The symfony Framework

. . . 452

The Zend Framework

. . . 453

Introducing the Zend Framework

. . . 453

Downloading and Installing the Zend Framework

. . . 454

Creating Your First Zend Framework-Driven Web Site

. . . 455

Searching the Web with Zend_Service_Yahoo

. . . 460

Summary

. . . 462

■ ^{CHAPTER 26} Introducing Oracle

. . . 463

Oracle’s Database Family

. . . 463

Express Edition (XE)

. . . 463

Standard Edition One

. . . 465

Standard Edition

. . . 465

Enterprise Edition

. . . 465

Personal Edition

. . . 466

Other Products in the Oracle Family

. . . 466

Developer and Client-Side Tools

. . . 466

Summary

. . . 467

■ ^{CHAPTER 27} Installing and Configuring Oracle Database XE

. . . 469

Ensuring Installation Prerequisites

. . . 469

Windows Installation Tasks

. . . 470

Windows Prerequisites

. . . 470

Downloading the Installation Files

. . . 470

Performing the Installation

. . . 470

Configuring Oracle and PHP

. . . 474

Linux Installation Tasks

. . . 474

Linux Prerequisites

. . . 475

Downloading the Installation Files

. . . 476

Performing the Installation

. . . 477

Configuring Oracle and PHP

. . . 478

Performing Post-Installation Tasks

. . . 479

Creating User Accounts

. . . 479

Summary

. . . 480

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■ ^{CHAPTER 28} Oracle Database XE Administration

. . . 481

Understanding the Oracle Architecture

. . . 481

Oracle Storage Structures

. . . 482

Oracle Memory Structures

. . . 485

Initialization Parameters

. . . 487

Connecting to the Database

. . . 489

Running SQL*Plus from the Command Line

. . . 489

Running SQL Commands Using the XE Home Page

. . . 492

Starting and Stopping Oracle Database XE

. . . 494

Starting Oracle Database XE

. . . 494

Stopping Oracle Database XE

. . . 495

Using Oracle-Supplied Utilities

. . . 496

Administration

. . . 497

Object Browser

. . . 497

SQL

. . . 498

Utilities

. . . 498

Application Builder

. . . 498

Troubleshooting in Oracle

. . . 499

Summary

. . . 500

■ ^{CHAPTER 29} Interacting with Oracle Database XE

. . . 501

XE Home Page

. . . 501

Installing the Oracle Database XE Client

. . . 501

Installing the Windows Client

. . . 502

Installing the Linux Client

. . . 503

Using SQL Command Line

. . . 504

Using SQL Developer

. . . 504

Using Application Express

. . . 506

Using PHP

. . . 510

Summary

. . . 511

■ ^{CHAPTER 30} From Databases to Datatypes

. . . 513

Creating and Managing Tablespaces

. . . 513

Tablespace Types

. . . 513

Creating a New Tablespace

. . . 515

Understanding Oracle Datatypes

. . . 516

Built-in Datatypes

. . . 516

ANSI-Supported Datatypes

. . . 522

(21)

Creating and Maintaining Tables

. . . 523

Creating a Table

. . . 523

Using Constraints

. . . 525

Setting Column Defaults

. . . 529

Creating a Table Using a Query Against Another Table

. . . 529

Modifying Table Characteristics

. . . 529

Creating and Maintaining Indexes

. . . 531

Using B-tree Indexes

. . . 531

Using Bitmap Indexes

. . . 532

Creating and Using Sequences

. . . 532

Summary

. . . 534

■ ^{CHAPTER 31} Securing Oracle Database XE

. . . 535

Security Terminology Overview

. . . 535

Security First Steps

. . . 536

Understanding Database Authentication

. . . 537

Database Authentication Overview

. . . 537

Database Administrator Authentication

. . . 537

User Accounts

. . . 540

Creating Users

. . . 540

Altering Users

. . . 542

Dropping Users

. . . 542

Becoming Another User

. . . 543

User-Related Data Dictionary Views

. . . 543

Understanding Database Authorization Methods

. . . 544

Profile Management

. . . 544

Using System Privileges

. . . 549

Using Object Privileges

. . . 551

Creating, Assigning, and Maintaining Roles

. . . 553

Using Database Auditing

. . . 558

Auditing Locations

. . . 558

Statement Auditing

. . . 559

Privilege Auditing

. . . 561

Schema Object Auditing

. . . 562

Protecting the Audit Trail

. . . 563

Summary

. . . 563

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■ ^{CHAPTER 32} PHP’s Oracle Functionality

. . . 565

Prerequisites

. . . 565

Using Database Connections

. . . 565

Connecting to the Database

. . . 566

Database Connection Strings

. . . 567

Disconnecting from the Database

. . . 570

Retrieving and Modifying Data

. . . 570

Preparing, Binding, and Executing Statements

. . . 571

Retrieving Table Rows

. . . 573

Inserting Rows

. . . 575

Modifying Rows

. . . 578

Deleting Rows

. . . 579

Counting Rows Selected or Affected

. . . 581

Retrieving Database Metadata

. . . 581

Viewing Database Characteristics

. . . 582

Viewing User Tables

. . . 583

Viewing Table Columns and Column Characteristics

. . . 584

Using Other Database Functions

. . . 587

oci_error()

. . . 587

oci_password_change()

. . . 588

Summary

. . . 589

■ ^{CHAPTER 33} Transactions

. . . 591

Using Transactions: Overview

. . . 591

Understanding Transaction Components

. . . 592

Explicit COMMIT Statement

. . . 592

Implicit COMMIT Statement

. . . 594

Explicit ROLLBACK Statement

. . . 594

The SAVEPOINT Statement

. . . 595

Performing Transactions Using PHP

. . . 597

Summary

. . . 600

■ ^{CHAPTER 34} Using HTML_Table with Advanced Queries

. . . 601

Using HTML_Table

. . . 601

Installing HTML_Table

. . . 602

Creating a Simple Table

. . . 603

Creating More Readable Row Output

. . . 605

Creating a Table from Database Data

. . . 606

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Leveraging Subqueries

. . . 607

Performing Comparisons with Subqueries

. . . 608

Determining Existence with Subqueries

. . . 609

Database Maintenance with Subqueries

. . . 610

Generalizing the Output Process

. . . 610

Sorting Output

. . . 612

Creating Paged Output

. . . 614

Listing Page Numbers

. . . 617

Summary

. . . 619

■ ^{CHAPTER 35} Using Views

. . . 621

Introducing Views

. . . 621

Creating and Executing User Views

. . . 622

Modifying a View

. . . 625

Deleting a View

. . . 626

Updating a View

. . . 626

Other View Types

. . . 627

Data Dictionary Views

. . . 627

Dynamic Performance Views

. . . 629

Using Views to Restrict Data Access

. . . 629

Incorporating Views into Web Applications

. . . 630

Summary

. . . 631

■ ^{CHAPTER 36} Oracle PL/SQL Subprograms

. . . 633

Should You Use PL/SQL Subprograms?

. . . 633

Subprogram Advantages

. . . 634

Subprogram Disadvantages

. . . 634

How Oracle Implements Subprograms

. . . 635

Creating a Stored Procedure

. . . 635

Parameters

. . . 637

Declaring and Setting Variables

. . . 638

PL/SQL Constructs

. . . 639

Creating and Using a Stored Function

. . . 644

Modifying, Replacing, or Deleting Subprograms

. . . 644

Integrating Subprograms into PHP Applications

. . . 645

Summary

. . . 647

. . . 675

Exporting Data

. . . 675

Using the SPOOL Command

. . . 675

Exporting Using GUI Utilities

. . . 676

Importing Data

. . . 680

Summary

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xxvii

■W. JASON GILMORE has been obsessing over all things open source for more than ten years, with a primary focus on Web development technologies.

He has been extensively published in publications such as Developer.com, TechTarget, and Linux Magazine, with his writings adopted for use within the United Nations and Ford Foundation educational programs. Jason is the author of four books, including the best-selling Beginning PHP and MySQL 5, Second Edition (http://www.beginningphpandmysql.com/), published by Apress.

Jason spends his days running Apress’s open source program and his evenings writing, coding, and consulting. He’s a founding board member of CodeMash (http://www.codemash.org/), an organization dedicated to educating the development community. When not in front of the computer, Jason can typically be found dreaming up home-remodeling projects, playing chess, and making homemade pasta. In his effort to occasionally get away from the keyboard, he recently bought, of all things, a piano.

■^{BOB BRYLA} is an Oracle 9i and 10g Certified Professional with more than 20 years of experience in database design, database application development, training, and database administration. He is an Internet database analyst and Oracle DBA at Lands’ End, Inc., in Dodgeville, Wisconsin. He is the author of several other Oracle DBA books for both the novice and seasoned professional.

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xxix

■^{MATT WADE} is a programmer, database developer, and system administrator.

He currently works for a large financial firm by day and freelances by night.

He has experience programming in several languages, though he most commonly utilizes PHP and C. On the database side of things, he regularly uses MySQL and Microsoft SQL Server. As an accomplished system administrator, he regularly has to maintain Windows servers and Linux boxes and prefers to deal with FreeBSD.

Matt resides in Jacksonville, Florida, with his wife, Michelle, and their three children, Matthew, Jonathan, and Amanda. When not working, Matt can be found fishing, doing something at his church, or playing some video game. Matt was the founder of Codewalkers.com, a leading resource for PHP developers, and ran the site until 2007.

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xxxi

A

lthough it’s the author who tends to receive all the credit, this material would never have seen the light of day without the tireless efforts of a truly talented supporting cast. Project managers Tracy Brown-Collins and Kylie Johnston deftly guided us through the wilderness from the very beginning, attempting to keep us on schedule despite our best efforts to do otherwise. Technical reviewer Matt Wade tracked down countless issues and provided invaluable feedback. Copy editor Jennifer Whipple did a fantastic job turning our gibberish into English. Editor and Oracle expert Jonathan Gennick helped improve both the book’s instructional and technical approaches throughout.

I’d also like to especially thank Oracle oracle Bob Bryla for joining me on this long but exciting project. You did a tremendous job, and I look forward to working with you again!

Of course, this book wouldn’t exist without the amazing contributions of the open source community and the groundbreaking efforts of the Oracle Corporation. Thank you for making such amazing software available to the world.

I’d like to thank Apress cofounder and publisher Gary Cornell, assistant publisher Dominic Shakeshaft, associate publisher Grace Wong, assistant publisher Jeff Pepper, and my other Apress colleagues for yet another opportunity to work with the greatest publisher on the planet!

Finally, I’d like to thank my friends and family for their best attempts to occasionally pry me away from the laptop. At least you tried!

W. Jason Gilmore Columbus, Ohio

I would like to thank the many people at Apress for helping me along this new and winding road, especially Jonathan Gennick for convincing me to get on board in the first place, Kylie Johnston for her relentless but appreciated schedule reminders, Matt Wade for seeing things during the technical edit that would have slipped by me otherwise, Jennifer Whipple for reminding me of all those pesky grammar rules from college that I have long forgotten, and Kelly Winquist for making me appreciate Adobe Acrobat Professional.

Thanks also to all of my professional colleagues, both past and present, who provided me with inspiration, guidance, courage, and many other intangibles without which this book would not be possible. The list is long, but I would be remiss if I did not mention my co-workers, friends, and managers at Lands’ End who provided expertise, advice, and M&Ms: Phil DeKok, Brook Swenson, Martha Graber, Joe Johnson, Karen Shelton, and Amy Rees.

Bob Bryla

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xxxiii

M

ahatma Gandhi once famously said, “First they ignore you, then they laugh at you, then they fight you, then you win.” Although there’s not yet any clear winner, the software industry seems to be following a similar path. Although the open source movement began back in the 1970s due to Richard Stallman’s printer-borne frustrations in an MIT computer lab, it wasn’t until the late 1990s that the community-driven approach to software development began to make any significant waves in the business environment.

And with it came gasps of both horror and hilarity among the proprietary software elite. After all, a bunch of volunteers could hardly produce code of a quality approaching, let alone surpassing, that which is built in the hallowed cathedrals of software development, right? Such guffaws rang increasingly loudly despite numerous clear successes in the open source community, such as the Apache dominating position in the Web server market and Linux’s meteoric rise to become one of the world’s most popular operating systems.

But soon it became apparent this approach did work after all, as was evidenced by the rapid adoption of open source solutions for commonplace tasks such as code editing, FTP transfer, file compression, databasing, and word processing. The commercial software industry responded with overt attempts to discredit the competing open source competitors, highlighting feature deficiencies, scaling problems, lack of traditional user support, and anything else that would justify its products’

often hefty price tags.

Yet more recently, many traditional software developers are coming to the conclusion that a more cooperative attitude must be adopted if they are going to survive, let alone compete, in this brave new world. Many have even determined that open source is actually a beneficial part of the ecosystem and are making great strides toward not only making sure their software interoperates with open source projects but also offering considerable contributions by way of resources and even code.

One of the most exciting such instances of the opportunities that can arise from such efforts is the ability to use PHP, an open source project that also happens to be the world’s most popular programming language for dynamic Web development, with Oracle, a proprietary database that also happens to be the world’s most popular solution for managing data. Although for some time it has been possible to use PHP and Oracle together, only recently have these efforts really begun to pay off because of increased activities in both camps by way of not only improvements to the interface but also to the creation of learning resources, documentation, and other utilities.

It seems as with most things in life, the success of the software development industry does not lie squarely within one extreme approach but rather somewhere in between. We hope this book will highlight the riches that can be wrought from a successful collaboration between the two.

Who This Book Is For

Although this book presumes the reader has no prior experience using PHP or Oracle, seasoned users of these technologies may find it equally satisfactory because the authors have strived to create a book that strikes a balance between tutorial and reference. Our goal is to provide you with a resource that can be repeatedly referred to as you progress from a novice to an experienced developer.

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Although basic introductions are often provided, this book does not seek to teach you funda- mental programming concepts. After all, the book is not titled Beginning Programming with PHP and Oracle. And it does not teach you HTML and Cascading Style Sheets (CSS). If you are a program- ming novice or are not yet versed in the aforementioned Web technologies, consider picking up one or several of the fine Apress books covering these topics.

Downloading the Code

Experimenting with the code found in this book is the most efficient way to understand the concepts presented within it. For your convenience, a ZIP file containing all of the examples is freely available for download from http://www.apress.com/.

Contacting the Authors

Jason loves corresponding with readers and invites you to e-mail him at [email protected].

Follow his latest activities at http://www.wjgilmore.com/.

To contact Bob Bryla, you can e-mail him at [email protected].

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1

■ ■ ■

Introducing PHP

I

n many ways the PHP language is representative of the stereotypical open source project, created to meet a developer’s otherwise unmet needs and refined over time to meet the needs of its growing community. As a budding PHP developer, it’s important you possess some insight into how the language has progressed, as it will help you to understand the language’s strengths, and to some extent the reasoning behind its occasional idiosyncrasies.

Additionally, because the language is so popular, having some understanding of the differences between the versions—most notably versions 4, 5, and 6—will help when evaluating Web hosting providers and PHP-driven applications for your own needs.

To help you quickly get up to speed in this regard, this chapter will get you acquainted with PHP’s features and version-specific differences. By the conclusion of this chapter, you’ll learn the following:

• How a Canadian developer’s Web page traffic counter spawned one of the world’s most popular scripting languages

• What PHP’s developers did to reinvent the language, making version 5 the best yet released

• Why PHP 6 is going to further propel PHP’s adoption in the enterprise

• Which features of PHP attract both new and expert programmers alike

■ ^Note

At the time of publication, PHP 6 was still a beta release, although many of the features are stable enough that they can safely be discussed throughout the course of the book. But be forewarned; some of these features could change before the final version is released.

History

The origins of PHP date back to 1995 when an independent software development contractor named Rasmus Lerdorf developed a Perl/CGI script that enabled him to know how many visitors were reading his online résumé. His script performed two tasks: logging visitor information, and displaying the count of visitors to the Web page. Because the Web as we know it today was still young at that time, tools such as these were nonexistent, and they prompted e-mails inquiring about Lerdorf’s scripts.

Lerdorf thus began giving away his toolset, dubbed Personal Home Page (PHP).

The clamor for the PHP toolset prompted Lerdorf to continue developing the language, with perhaps the most notable early change being a new feature for converting data entered in an HTML form into symbolic variables, encouraging exportation into other systems. To accomplish this, he opted to continue development in C code rather than Perl. Ongoing additions to the PHP toolset culminated in November 1997 with the release of PHP 2.0, or Personal Home Page/Form Interpreter

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(PHP/FI). As a result of PHP’s rising popularity, the 2.0 release was accompanied by a number of enhancements and improvements from programmers worldwide.

The new PHP release was extremely popular, and a core team of developers soon joined Lerdorf.

They kept the original concept of incorporating code directly alongside HTML and rewrote the parsing engine, giving birth to PHP 3.0. By the June 1998 release of version 3.0, more than 50,000 users were using PHP to enhance their Web pages.

Development continued at a hectic pace over the next two years, with hundreds of functions being added and the user count growing in leaps and bounds. At the beginning of 1999, Netcraft (http://www.netcraft.com/), an Internet research and analysis company, reported a conservative estimate of a user base of more than 1 million, making PHP one of the most popular scripting languages in the world. Its popularity surpassed even the greatest expectations of the developers, as it soon became apparent that users intended to use PHP to power far larger applications than originally anticipated. Two core developers, Zeev Suraski and Andi Gutmans, took the initiative to completely rethink the way PHP operated, culminating in a rewriting of the PHP parser, dubbed the Zend scripting engine. The result of this work was in the PHP 4 release.

■ ^Note

In addition to leading development of the Zend engine and playing a major role in steering the overall development of the PHP language, Suraski and Gutmans are cofounders of Zend Technologies Ltd. (http://

www.zend.com/). Zend is the most visible provider of products and services for developing, deploying, and managing PHP applications. Check out the Zend Web site for more about the company’s offerings, as well as an enormous amount of free learning resources.

PHP 4

On May 22, 2000, roughly 18 months after the first official announcement of the new development effort, PHP 4.0 was released. Many considered the release of PHP 4 to be the language’s official debut within the enterprise development scene, an opinion backed by the language’s meteoric rise in popularity. Just a few months after the major release, Netcraft estimated that PHP had been installed on more than 3.6 million domains.

PHP 4 added several enterprise-level improvements to the language, including the following:

Improved resource handling: One of version 3.X’s primary drawbacks was scalability. This was largely because the designers underestimated how rapidly the language would be adopted for large-scale applications. The language wasn’t originally intended to run enterprise-class Web sites, and continued interest in using it for such purposes caused the developers to rethink much of the language’s mechanics in this regard.

Object-oriented support: Version 4 incorporated a degree of object-oriented functionality, although it was largely considered an unexceptional and even poorly conceived implementation. Nonetheless, the new features played an important role in attracting users used to working with traditional object-oriented programming (OOP) languages. Standard class and object development methodologies were made available in addition to features such as object over- loading and run-time class information. A much more comprehensive OOP implementation has been made available in version 5 and is introduced in Chapter 6.

Native session-handling support: HTTP session handling, available to version 3.X users through the third-party package PHPLIB (http://phplib.sourceforge.net) was natively incorporated into version 4. This feature offers developers a means for tracking user activity and preferences with unparalleled efficiency and ease. Chapter 18 covers PHP’s session-handling capabilities.

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Encryption: The MCrypt (http://mcrypt.sourceforge.net) library was incorporated into the default distribution, offering users both full and hash encryption using encryption algorithms including Blowfish, MD5, SHA1, and TripleDES, among others. Chapter 21 delves into PHP’s encryption capabilities.

ISAPI support: ISAPI support offered users the ability to use PHP in conjunction with Microsoft’s IIS Web server. Chapter 2 shows you how to install PHP on both the IIS and Apache Web servers.

Native COM/DCOM support: Another bonus for Windows users is PHP 4’s ability to access and instantiate COM objects. This functionality opened up a wide range of interoperability with Windows applications.

Native Java support: In another boost to PHP’s interoperability, support for binding to Java objects from a PHP application was made available in version 4.0.

Perl Compatible Regular Expressions (PCRE) library: The Perl language has long been heralded as the reigning royalty of the string parsing kingdom. The developers knew that powerful regular expression functionality would play a major role in the widespread acceptance of PHP and opted to simply incorporate Perl’s functionality rather than reproduce it, rolling the PCRE library package into PHP’s default distribution (as of version 4.2.0). Chapter 9 introduces this important feature in great detail and offers a general introduction to the often confusing regular expression syntax.

In addition to these features, literally hundreds of functions were added to version 4, greatly enhancing the language’s capabilities. Many of these functions are discussed throughout the course of the book.

PHP 4 represented a gigantic leap forward in the language’s maturity, offering new features, power, and scalability that swayed an enormous number of burgeoning and expert developers alike.

Yet the PHP development team wasn’t content to sit on their hands for long and soon set upon another monumental effort, one that could establish the language as the 800-pound gorilla of the Web scripting world: PHP 5.

PHP 5

Version 5 was yet another watershed in the evolution of the PHP language. Although previous major releases had enormous numbers of new library additions, version 5 contains improvements over existing functionality and adds several features commonly associated with mature programming language architectures:

Vastly improved object-oriented capabilities: Improvements to PHP’s object-oriented archi- tecture is version 5’s most visible feature. Version 5 includes numerous functional additions such as explicit constructors and destructors, object cloning, class abstraction, variable scope, and interfaces, and a major improvement regarding how PHP handles object management.

Chapters 6 and 7 offer thorough introductions to this topic.

Try/catch exception handling: Devising custom error-handling strategies within structural programming languages is, ironically, error-prone and inconsistent. To remedy this problem, version 5 supports exception handling. Long a mainstay of error management in many languages, such as C++, C#, Python, and Java, exception handling offers an excellent means for standard- izing your error-reporting logic. This convenient methodology is introduced in Chapter 8.

Improved XML and Web Services support: XML support is now based on the libxml2 library, and a new and rather promising extension for parsing and manipulating XML, known as SimpleXML, has been introduced. In addition, a SOAP extension is now available. In Chapter 20, these two extensions are introduced, along with a number of slick third-party Web Services extensions.

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Native support for SQLite: Always keen on choice, the developers added support for the powerful yet compact SQLite database server (http://www.sqlite.org/). SQLite offers a convenient solution for developers looking for many of the features found in some of the heavyweight database products without incurring the accompanying administrative overhead. PHP’s support for this powerful database engine is introduced in Chapter 22.

■ ^Note

The enhanced object-oriented capabilities introduced in PHP 5 resulted in an additional boost for the language: it opened up the possibility for cutting-edge frameworks to be created using the language. Chapter 25 introduces you to one of the most popular frameworks available today, namely the Zend Framework (http://

framework.zend.com/).

With the release of version 5, PHP’s popularity hit what was at the time a historical high, having been installed on almost 19 million domains, according to Netcraft. PHP was also by far the most popular Apache module, available on almost 54 percent of all Apache installations, according to Internet services consulting firm E-Soft Inc. (http://www.securityspace.com/).

PHP 6

At press time, PHP 6 was in beta and scheduled to be released by the conclusion of 2007. The decision to designate this a major release (version 6) is considered by many to be a curious one, in part because only one particularly significant feature has been added— Unicode support. However, in the program- ming world, the word significant is often implied to mean sexy or marketable, so don’t let the addition of Unicode support overshadow the many other important features that have been added to PHP 6.

A list of highlights is found here:

• Unicode support: Native Unicode support has been added.

• Security improvements: A considerable number of security-minded improvements have been made that should greatly decrease the prevelance of security-related gaffes that to be frank aren’t so much a fault of the language, but are due to inexperienced programmers running with scissors, so to speak. These changes are discussed in Chapter 2.

• New language features and constructs: A number of new syntax features have been added, including, most notably, a 64-bit integer type, a revamped foreach looping construct for multidimensional arrays, and support for labeled breaks. Some of these features are discussed in Chapter 3.

At press time, PHP’s popularity was at a historical high. According to Netcraft, PHP has been installed on more than 20 million domains. According to E-Soft Inc., PHP remains the most popular Apache module, available on more than 40 percent of all Apache installations.

So far, this chapter has discussed only version-specific features of the language. Each version shares a common set of characteristics that play a very important role in attracting and retaining a large user base. In the next section, you’ll learn about these foundational features.

■ ^Note

You might be wondering why versions 4, 5, and 6 were mentioned in this chapter. After all, isn’t only the newest version relevant? While you’re certainly encouraged to use the latest stable version, versions 4 and 5 remain in widespread use and are unlikely to go away anytime soon. Therefore having some perspective regarding each version’s capabilities and limitations is a good idea, particularly if you work with clients who might not be as keen to keep up with the bleeding edge of PHP technology.

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General Language Features

Every user has his or her own specific reason for using PHP to implement a mission-critical application, although one could argue that such motives tend to fall into four key categories: practicality, power, possibility, and price.

Practicality

From the very start, the PHP language was created with practicality in mind. After all, Lerdorf’s original intention was not to design an entirely new language, but to resolve a problem that had no readily available solution. Furthermore, much of PHP’s early evolution was not the result of the explicit intention to improve the language itself, but rather to increase its utility to the user. The result is a language that allows the user to build powerful applications even with a minimum of knowledge.

For instance, a useful PHP script can consist of as little as one line; unlike C, there is no need for the mandatory inclusion of libraries. For example, the following represents a complete PHP script, the purpose of which is to output the current date, in this case one formatted like September 23, 2007:

<?php echo date("F j, Y");?>

Don’t worry if this looks foreign to you. In later chapters, the PHP syntax will be explained in great detail. For the moment just try to get the gist of what’s going on.

Another example of the language’s penchant for compactness is its ability to nest functions. For instance, you can effect numerous changes to a value on the same line by stacking functions in a particular order. The following example produces a string of five alphanumeric characters such as a3jh8:

$randomString = substr(md5(microtime()), 0, 5);

PHP is a loosely typed language, meaning there is no need to explicitly create, typecast, or destroy a variable, although you are not prevented from doing so. PHP handles such matters internally, creating variables on the fly as they are called in a script, and employing a best-guess formula for automatically typecasting variables. For instance, PHP considers the following set of statements to be perfectly valid:

<?php

$number = "5"; // $number is a string

$sum = 15 + $number; // Add an integer and string to produce integer $sum = "twenty"; // Overwrite $sum with a string.

?>

PHP will also automatically destroy variables and return resources to the system when the script completes. In these and in many other respects, by attempting to handle many of the administrative aspects of programming internally, PHP allows the developer to concentrate almost exclusively on the final goal, namely a working application.

Power

PHP developers have more than 180 libraries at their disposal, collectively containing well over 1,000 functions. Although you’re likely aware of PHP’s ability to interface with databases, manipulate form information, and create pages dynamically, you might not know that PHP can also do the following:

• Create and manipulate Adobe Flash and Portable Document Format (PDF) files

• Evaluate a password for guessability by comparing it to language dictionaries and easily broken patterns

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• Parse even the most complex of strings using the POSIX and Perl-based regular expression libraries

• Authenticate users against login credentials stored in flat files, databases, and even Microsoft’s Active Directory

• Communicate with a wide variety of protocols, including LDAP, IMAP, POP3, NNTP, and DNS, among others

• Tightly integrate with a wide array of credit-card processing solutions

And this doesn’t take into account what’s available in the PHP Extension and Application Repository (PEAR), which aggregates hundreds of easily installable open source packages that serve to further extend PHP in countless ways. You can learn more about PEAR in Chapter 11. In the coming chapters you’ll learn about many of these libraries and several PEAR packages.

Possibility

PHP developers are rarely bound to any single implementation solution. On the contrary, a user is typically fraught with choices offered by the language. For example, consider PHP’s array of database support options. Native support is offered for more than 25 database products, including Adabas D, dBase, Empress, FilePro, FrontBase, Hyperwave, IBM DB2, Informix, Ingres, InterBase, mSQL, Microsoft SQL Server, MySQL, Oracle, Ovrimos, PostgreSQL, Solid, Sybase, Unix dbm, and Velocis.

In addition, abstraction layer functions are available for accessing Berkeley DB–style databases.

Several generalized database abstraction solutions are also available, among the most popular being PDO (http://www.php.net/pdo) and MDB2 (http://pear.php.net/package/MDB2). Finally, if you’re looking for an object relational mapping (ORM) solution, projects such as Propel (http://propel.

phpdb.org/trac/) should fit the bill quite nicely.

PHP’s flexible string-parsing capabilities offer users of differing skill sets the opportunity to not only immediately begin performing complex string operations but also to quickly port programs of similar functionality (such as Perl and Python) over to PHP. In addition to more than 85 string- manipulation functions, both POSIX- and Perl-based regular expression formats are supported.

Do you prefer a language that embraces procedural programming? How about one that embraces the object-oriented paradigm? PHP offers comprehensive support for both. Although PHP was originally a solely functional language, the developers soon came to realize the importance of offering the popular OOP paradigm and took the steps to implement an extensive solution.

The recurring theme here is that PHP allows you to quickly capitalize on your current skill set with very little time investment. The examples set forth here are but a small sampling of this strategy, which can be found repeatedly throughout the language.

Price

PHP is available free of charge! Since its inception, PHP has been without usage, modification, and redistribution restrictions. In recent years, software meeting such open licensing qualifications has been referred to as open source software. Open source software and the Internet go together like bread and butter. Open source projects such as Sendmail, Bind, Linux, and Apache all play enormous roles in the ongoing operations of the Internet at large. Although open source software’s free availability has been the point most promoted by the media, several other characteristics are equally important if not more so:

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Free of licensing restrictions imposed by most commercial products: Open source software users are freed of the vast majority of licensing restrictions one would expect of commercial counterparts. Although some discrepancies do exist among license variants, users are largely free to modify, redistribute, and integrate the software into other products.

Open development and auditing process: Although not without incidents, open source soft- ware has long enjoyed a stellar security record. Such high-quality standards are a result of the open development and auditing process. Because the source code is freely available for anyone to examine, security holes and potential problems are rapidly found and fixed. This advantage was perhaps best summarized by open source advocate Eric S. Raymond, who wrote “Given enough eyeballs, all bugs are shallow.”

Participation is encouraged: Development teams are not limited to a particular organization.

Anyone who has the interest and the ability is free to join the project. The absence of member restrictions greatly enhances the talent pool for a given project, ultimately contributing to a higher-quality product.

Summary

Understanding more about the PHP language’s history and widely used versions is going to prove quite useful as you become more acquainted with the language and begin seeking out both hosting providers and third-party solutions. This chapter satisfied that requirement by providing some insight into PHP’s history and an overview of version 4, 5, and 6’s core features.

In Chapter 2, prepare to get your hands dirty, as you’ll delve into the PHP installation and configuration process, and learn more about what to look for when searching for a Web hosting provider.

Although readers often liken these types of chapters to scratching nails on a chalkboard, you can gain a lot from learning more about this process. Much like a professional cyclist or race car driver, the programmer with hands-on knowledge of the tweaking and maintenance process often holds an advantage over those without by virtue of a better understanding of both the software’s behaviors and quirks. So grab a snack and cozy up to your keyboard—it’s time to build.

Beginning PHP and Oracle