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The definitive guide to SQLite
Books for professionals By professionals ® The Definitive Guide to SQLite Dear Reader, Outside of the world of enterprise computing there is one database that enables a huge range of software and hardware to flex relational database capabilities, without the baggage and cost of traditional database management systems. That database is SQLite—an embeddable database with an amazingly small footprint, yet it can handle databases of enormous size. SQLite comes equipped with an array of powerful features available through a host of programming and development environments. It is supported by languages such as C, Java, Perl, PHP, Python, Ruby, TCL, and more. The Definitive Guide to SQLite, 2nd Edition is devoted to complete cover- age of the latest version of this powerful database. It offers a thorough over- view of SQLite’s capabilities and APIs. The book also uses SQLite as the basis for helping newcomers make their first foray into database development. In only a short time you can be writing programs as diverse as a server-side browser plug-in or the next great iPhone or Android application! • You’ll learn about SQLite extensions for C, Java, Perl, PHP, Python, Ruby, and Tcl. • You’ll get solid coverage of SQLite internals. • You’ll explore developing iOS (iPhone) and Android applications with SQLite. SQLite is the solution chosen for thousands of products around the world, from mobile phones and GPS devices to set-top boxes and web browsers. You almost certainly use SQLite every day without even realizing it! Sincerely, Grant Allen and Mike Owens US $49.99 Shelve in: Databases User level: Intermediate–Advanced Mike Owens THE APRESS ROADMAP Beginning Database Design Beginning SQL Queries Applied Mathematics for Database Professionals The Definitive Guide to SQLite www.apress.com SOURCE CODE ONLINE Companion eBook See last page for details on $10 eBook version ISBN 978-1-4302-3225-4 9 781430 232254 54999 Allen Owens SECOND EDITION SQLite Companion eBook Available The Definitive Guide to The eXperT’s Voice ® in open source SECOND EDITION Grant Allen and Mike Owens Take control of this compact and powerful tool to embed sophisticated SQL databases within your applications The Definitive Guide to SQLite Grant Allen The Definitive Guide to SQLite Second Edition ■ ■ ■ Grant Allen Mike Owens The Definitive Guide to SQLite, Second Edition Copyright © 2010 by Grant Allen and Mike Owens 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): 978-1-4302-3225-4 ISBN-13 (electronic): 978-1-4302-3226-1 Printed and bound in the United States of America 9 8 7 6 5 4 3 2 1 Trademarked names, logos, and images may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, logo, or image we use the names, logos, and images only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. President and Publisher: Paul Manning Lead Editor: Jonathan Gennick Technical Reviewer: Richard Hipp Editorial Board: Steve Anglin, Mark Beckner, Ewan Buckingham, Gary Cornell, Jonathan Gennick, Jonathan Hassell, Michelle Lowman, Matthew Moodie, Duncan Parkes, Jeffrey Pepper, Frank Pohlmann, Douglas Pundick, Ben Renow-Clarke, Dominic Shakeshaft, Matt Wade, Tom Welsh Coordinating Editor: Jennifer L. Blackwell Copy Editor: Kim Wimpsett Production Support: Patrick Cunningham Indexer: Julie Grady Artist: April Milne Cover Designer: Anna Ishchenko Distributed to the book trade worldwide by Springer Science+Business Media, LLC., 233 Spring Street, 6th Floor, New York, NY 10013. Phone 1-800-SPRINGER, fax (201) 348-4505, e-mail orders-ny@springer-sbm.com, or visit www.springeronline.com. For information on translations, please e-mail rights@apress.com, or visit www.apress.com. 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To my mother for her endless support of all my crazy ideas iv Contents at a Glance About the Authors xvi About the Technical Reviewer xvii Acknowledgments xviii Introduction xix ■Chapter 1: Introducing SQLite 1 ■Chapter 2: Getting Started 17 ■Chapter 3: SQL for SQLite 47 ■Chapter 4: Advanced SQL for SQLite 87 ■Chapter 5: SQLite Design and Concepts 125 ■Chapter 6: The Core C API 153 ■Chapter 7: The Extension C API 195 ■Chapter 8: Language Extensions 219 ■Chapter 9: iOS Development with SQLite 253 ■Chapter 10: Android Development with SQLite 279 ■Chapter 11: SQLite Internals and New Features 303 Index 323 v Contents About the Authors xvi About the Technical Reviewer xvii Acknowledgments xviii Introduction xix ■Chapter 1: Introducing SQLite 1 An Embedded Database 1 A Developer’s Database 2 An Administrator’s Database 3 SQLite History 3 Who Uses SQLite 4 Architecture 5 The Interface 6 The Compiler 6 The Virtual Machine 6 The Back End 7 Utilities and Test Code 8 SQLite’s Features and Philosophy 8 Zero Configuration 8 Portability 8 Compactness 9 ■ CONTENTS vi Simplicity 9 Flexibility 9 Liberal Licensing 9 Reliability 10 Convenience 10 Performance and Limitations 11 Who Should Read This Book 13 How This Book Is Organized 14 Additional Information 15 Summary 15 ■Chapter 2: Getting Started 17 Where to Get SQLite 17 SQLite on Windows 18 Getting the Command-Line Program 18 Getting the SQLite DLL 21 Compiling the SQLite Source Code on Windows 22 Building the SQLite DLL with Microsoft Visual C++ 25 Building a Dynamically Linked SQLite Client with Visual C++ 27 Building SQLite with MinGW 28 SQLite on Linux, Mac OS X, and Other POSIX Systems 30 Binaries and Packages 30 Compiling SQLite from Source 31 The Command-Line Program 32 The CLP in Shell Mode 33 The CLP in Command-Line Mode 34 ■ CONTENTS vii Database Administration 35 Creating a Database 35 Getting Database Schema Information 37 Exporting Data 39 Importing Data 40 Formatting 40 Exporting Delimited Data 41 Performing Unattended Maintenance 41 Backing Up a Database 42 Getting Database File Information 44 Other SQLite Tools 45 Summary 46 ■Chapter 3: SQL for SQLite 47 The Example Database 47 Installation 48 Running the Examples 49 Syntax 50 Commands 51 Literals 52 Keywords and Identifiers 53 Comments 53 Creating a Database 53 Creating Tables 53 Altering Tables 54 Querying the Database 55 Relational Operations 55 select and the Operational Pipeline 57 Filtering 59 ■ CONTENTS viii Limiting and Ordering 64 Functions and Aggregates 66 Grouping 67 Removing Duplicates 72 Joining Tables 72 Names and Aliases 77 Subqueries 79 Compound Queries 81 Conditional Results 83 Handling Null in SQLite 84 Summary 86 ■Chapter 4: Advanced SQL for SQLite 87 Modifying Data 87 Inserting Records 87 Updating Records 91 Deleting Records 92 Data Integrity 92 Entity Integrity 93 Domain Integrity 97 Storage Classes 101 Views 104 Indexes 106 Triggers 108 Transactions 111 Transaction Scopes 111 Conflict Resolution 112 Database Locks 115 Deadlocks 116 Transaction Types 117 [...]... precautions to guard against memory leaks Once the statement has been broken into tokens, evaluated, and recast in the form of a parse tree, the parser passes the tree down to the code generator The code generator translates the parse tree into a kind of assembly language specific to SQLite This assembly language consists of instructions that are executable by its virtual machine The code generator’s sole... Generator Database Virtual Machine Figure 1-2 SQLite s architecture 5 CHAPTER 1 ■ INTRODUCING SQLITE The Interface The interface is the top of the stack and consists of the SQLite C API It is the means through which programs, scripting languages, and libraries alike interact with SQLite Literally, this is where you as developer, administrator, student, or mad scientist talk to SQLite The Compiler The. .. process starts with the tokenizer and parser They work together to take a Structured Query Language (SQL) statement in text form, validate its syntax, and then convert it to a hierarchical data structure that the lower layers can more easily manipulate SQLite s tokenizer is hand-coded Its parser is generated by SQLite s custom parser generator, which is called Lemon The Lemon parser generator is designed... Consider the processes found in Figure 1-1 One is a Perl script, another is a standard C/C++ program, and the last is an Apache-hosted PHP script, all using SQLite The Perl script imports the DBI: :SQLite module, which in turn is linked to the SQLite C API, pulling in the SQLite library The PHP library works similarly, as does the C++ program Ultimately, all three processes interface with the SQLite C... I'd like to express my gratitude to the entire team at Apress, especially Jonathan Gennick, my fabulous editor, and Jennifer Blackwell, my wonderful project manager They made it feel like the book was almost writing itself! OK, that’s a lie, but really, they made the experience of producing The Definitive Guide to SQLite an enjoyable and rewarding one I’d also like to pass on a huge thank you to D Richard... materialization The end result is that there is a crisp, well-defined separation between the front end (SQL compiler) and back end (storage system), allowing the two to be coded independently of each other This design makes it easier to add new features to the database engine, is faster to debug, and results in better overall reliability Flexibility Several factors work together to make SQLite a very flexible database... just says to the OS interface, “Lock this file,” and the OS interface figures out how to do that 7 CHAPTER 1 ■ INTRODUCING SQLITE based on the operating system on which it happens to be running Not only does the OS interface keep code simple and tidy in the other modules, but it also keeps the messy issues cleanly organized and at arm’s length in one place This makes it easier to port SQLite to different... But the words speedy, fast, peppy, or quick are rather subjective terms To be perfectly honest, there are things SQLite can do faster than other databases, and there are things that it cannot Suffice it to say, within the parameters for which it has been designed, SQLite can be said to be consistently fast and efficient across the board SQLite uses B-trees for indexes and B+-trees for tables, the same... “Introducing SQLite, ” introduces the main features of SQLite, its origin and history, and the scope and objectives of this book (you are reading this now!) Chapter 2, “Getting Started,” covers how to obtain and use SQLite It illustrates how to get SQLite in binary and source form, as well as how to compile and build it on a variety of platforms It explains how to use the SQLite commandline utility to create... comment The program consists of 15 instructions These instructions, performed in this particular order with the given operands, will return the name field of the first ten records in the episodes table (which is part of the example database included with this book) In many ways, the VDBE is the heart of SQLite All of the modules before it work to create a VDBE program, while all modules after it exist to . applications The Definitive Guide to SQLite Grant Allen The Definitive Guide to SQLite Second Edition ■ ■ ■ Grant Allen Mike Owens The Definitive Guide to SQLite, . Started 17 Where to Get SQLite 17 SQLite on Windows 18 Getting the Command-Line Program 18 Getting the SQLite DLL 21 Compiling the SQLite Source Code on Windows 22 Building the SQLite DLL with. Administrator’s Database 3 SQLite History 3 Who Uses SQLite 4 Architecture 5 The Interface 6 The Compiler 6 The Virtual Machine 6 The Back End 7 Utilities and Test Code 8 SQLite s Features