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)

Summary


This chapter introduced us to a new concept: Prepared Statements. We have seen how they simplify our queries and further protect us from SQL syntax errors and code vulnerabilities. We also took a look at how to work with BLOBs using streams so that we don't run the risk of query failures. Our application can now be used to upload and show cover images for the books in the database.

In the next chapter, we shall see how to determine the number of rows in a result set, which is necessary to paginate long lists of items. (The most common example is a search engine that breaks the result list into 10 results per page.) Also, we will familiarize ourselves with a new concept: scrollable cursors that will allow us to fetch a subset of rows from a result set starting at a specified position.