Book Image

Learning PHP Data Objects

By : Dennis Popel
Book Image

Learning PHP Data Objects

By: Dennis Popel

Overview of this book

PDO is lighter, faster, and more powerful than existing PHP data abstraction interfaces. PDO is a common interface to different databases that must be used with a database-specific PDO driver to access a particular database server: the PDO extension does not provide a database abstraction by itself; it doesn't rewrite SQL, emulate missing database features, or perform any database functions using by itself. It performs the same role as other classic database abstraction layers such as ODBC and JDBC: it's a query abstraction layer that abstracts the mechanism for accessing a database and manipulating the returned records; each database driver that implements the PDO interface can also expose database-specific features as regular extension functions. ¬ PDO ships with PHP 5.1, and is available as an extension for PHP 5.0; it requires the new object-oriented features of PHP 5, and cannot run with earlier versions of PHP.This book will teach you how to use the PDO, including its advanced features. Readers need to be aware of the basics of data abstraction and should be familiar with PHP.
Table of Contents (13 chapters)

Advantages of Separating the Model

So far, almost all of the files that generate front-end pages don't contain data access logic and are easier to manage. On the other hand, the model classes can be used from outside our application, and additional pages can be quickly created to represent the information in the database in other formats such as XML.

For example, consider the following page (which we will call books.xml.php):

* This page lists all the books we have as an XML data structure
* PDO Library Management example application
* @author Dennis Popel
// Don't forget the include
// Set the content type to be XML
header('Content-Type: application/xml');
// Get the books list
$books = Model::getBooksWithAuthors();
// Echo XML declaration and open root element
echo '<?xml version="1.0"?>', "\n";
echo "<books>\n";
// Now iterate over every book and display it
while($b = $books->fetch())
<book id="<?=$b->id?>"...