book

Beginning Perl

by Curtis Ovid Poe

September 2012

Beginner

744 pages

15h 48m

English

Wrox

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Perl TodayGetting PerlThe Perl CommunityUsing perldocUsing a Terminal WindowCreating Hello, World!Summary
CPAN and METACPANCPAN ClientsSummary
What is Programming?A Few Things to Note Before Getting StartedScalarsArraysHashesSlicesContextScopeStrict, Warnings, and DiagnosticsPerl’s Built-in VariablesSummary
Using ScalarsArray and List FunctionsBuilt-in Hash FunctionsScoping KeywordsSummary
Using the if Statementfor/foreach loopsUsing while/until LoopsStatement Modifiersgiven/whenSummary
References 101Working with ReferencesSummary
Subroutine SyntaxReturning DataFAIL!Subroutine ReferencesPrototypesRecursionThings to Watch ForSummary

Basic MatchingAdvanced MatchingCommon Regular Expression IssuesSummary
Basic File HandlingDirectoriesUnicodeUseful ModulesSummary
Basic Sortingmap and grepPutting It All TogetherSummary
Namespaces and PackagesSubroutines in Other PackagesBEGIN, UNITCHECK, CHECK, INIT, and ENDPlain Old Documentation (POD)Creating and Installing ModulesSummary
What Are Objects? The Ævar the Personal ShopperThree Rules of Perl OOObjects – Another ViewA Brief RecapGotchasSummary
Understanding Basic Moose SyntaxAdvanced Moose SyntaxMoose Best PracticesSummary
Basic TestsUnderstanding Test::More Test FunctionsUsing Other Testing ModulesUnderstanding xUnit Style Using TestingSummary
A Brief Introduction to HTTPWeb ClientsSummary
Using the DBISelecting Basic DataSummary
The Command LineOther ProgramsSummary
Using CSV DataUnderstanding Basic XMLHandling DatesUnderstanding Your ProgramSummary
What Next?Understanding Object-Relational MappersUsing the Template ToolkitUsing Catalyst to Build AppsSummary

Content preview from Beginning Perl

Chapter 16 Databases

WHAT YOU WILL LEARN IN THIS CHAPTER:

Understanding Perl’s DBI module
Connecting to databases
Selecting data from databases
Using binding parameters
Changing your data
Using transactions

WROX.COM CODE DOWNLOAD FOR THIS CHAPTER

The wrox.com code downloads for this chapter are found at http://www.wrox.com/remtitle.cgi?isbn=1118013847 on the Download Code tab. The code for this chapter is divided into the following major examples:

example_16_1_fetch.pl
lib/MyDatabase.pm
listing_16_1_make_database.pl
listing_16_2_populate_database.pl
listing_16_3_select.pl

A database is a place to store your data. It can be a regular file, a sheet of paper, or a hierarchical database such as IMS (no longer widely used). Today, when most people say “database,” they’re referring to what most people call relational databases. If you have a background in programming, you’ve probably heard of several of them, such as MySQL, PostgreSQL, Oracle, Sybase, and many others. Each of these offers a variety of different features, some favoring data integrity, others focused on performance, and some striving for both.

In this chapter you acquire a minimum knowledge of using databases in Perl. You will use the SQLite database and Perl’s DBI module. I chose SQLite because it’s easy to install and Perl’s DBI module because it is the standard for connecting to databases. There are other tools, such as object-relational mappers (ORMs) that try to hide some of the complexity of databases, but under ...