One of the consideration that users of Open Source programming languages have make is which one of many ways to do any particular task. Open Source tends to result in lots of very clever facilities being provided, many of which overlap in their use, and many modules being provided via libraries such as Pear and Pecl [PHP names being used]. A good example of this is database access - even when you've selected you main database engine you may be left with a baffling array of different ways to access it. I've just completed a short demonstration piece that shows our different pieces of code for accessing the same MySQL database.
I have four different ways I can talk to MySQL ...
routines. The "original". Quick and easy to code. For a single database connection, there's no need to pass around a "which connection" variable. Gets a bit messy when you may want to make several connections, as you have to then switch to using a connection variable (so you may need to refactor) and horribly tied to MySQL.
routines, using a functional (structured) approach. Very similar in many ways to the mysql_
routines, but you have to pass around a "which connection" variable. So this avoids you walking into a cul-de-sac in your early coding, as you can easily add another connection later. Still horribly tied to MySQL.
routines, using an OO approach. If you're writing in an object oriented mode, these are far nicer to use - you set up connection objects, get back query objects, and the whole thing naturally follows the OO paradigm. There's no way you can even be tempted along a single connection approach. Oh - but still tied to MySQL ... to a slightly lesser extent.
d) Using PDO
. The PHP Data Objects (PDO) extension defines a lightweight, consistent interface for accessing databases in PHP. Each database driver that implements the PDO interface can expose database-specific features as regular extension functions. So PDO lets you state once that it's MySQL you're using and then go ahead with your code without having to keep saying mysql-this and mysql-that. You do still need to be careful not to be tempted into using facilities which are MySQL only, but with care you can write more portable code.
The source code of the demonstration is [here]
and you can see the sort of results it would produce when run [here]
We have a brief section on how you may use PHP to talk to the MySQL database on our MySQL course
, and we cover talking to various SQL databases including SQLite and MySQL on our PHP Courses
. (written 2011-09-24)
Associated topics are indexed underH113 - Using MySQL Databases in PHP Pages 
How to display information from a database within a web page - (2010-11-07) 
The future of MySQL - (2010-01-03) 
MySQL stored procedures / their use on the web from PHP - (2009-10-10) 
Using print_r in PHP to explore mysql database requests - (2009-10-01) 
Helping new arrivals find out about source code examples - (2009-08-03) 
Grouping rows for a summary report - MySQL and PHP - (2009-06-27) 
Setting up a MySQL database from PHP - (2009-03-08) 
Keeping PHP code in database and running it - (2009-01-09) 
Uploading to a MySQL database through PHP - examples and common questions - (2008-03-02) 
Dates, times, clickable diarys in PHP - (2006-12-28) 
What is an SQL injection attack? - (2006-11-27) 
Display an image from a MySQL database in a web page via PHP - (2006-11-22) 
Paging through hundreds of entries - (2006-11-05) 
Viewing images held in a MySQL database via PHP - (2006-05-17) 
Database design - get it right from first principles - (2006-04-02) 
Checking for MySQL errors - (2006-03-15) 
Saving a MySQL query results to your local disc for Excel - (2006-01-29) 
Giving the researcher power over database analysis - (2006-01-22) 
MySQL - an FAQ - (2005-12-03) 
mysql_connect or mysql_pconnect in PHP? - (2004-10-30)S159 - MySQL 5 and PHP 5 
PHP4 v PHP5 - Object Model Difference - (2009-05-11) 
Diagrams to show you how - Tomcat, Java, PHP - (2008-08-22) 
Upgrade from PHP 4 to PHP 5 - the TRY issue - (2008-08-15) 
Connecting to MySQL 5 from PHP on Mac OSX Leopard - (2007-12-03) 
What software version do we teach? - (2007-10-31) 
MySQL - Password security (authentication protocol) - (2007-04-02) 
MySQL - a score of things to remember - (2005-11-12)S156 - Interfacing Applications to MySQL Databases 
Needle in a haystack - finding the web server overload - (2011-09-18) 
Perl - database access - DBD, DBI and DBIx modules - (2010-12-22) 
Joining a MySQL table from within a Python program - (2010-06-02) 
Connecting Python to sqlite and MySQL databases - (2010-04-28) 
Checking the database connection manually - (2009-08-28) 
Mysqldump fails as a cron job - a work around - (2009-06-30) 
Hiding a MySQL database behind a web page - (2008-11-15) 
Downloading data for use in Excel (from PHP / MySQL) - (2008-01-25) 
Easy selection of multiple SQL conditions from PHP - (2007-11-30) 
Using a MySQL database to control mod_rewrite via PHP - (2007-10-06) 
Python to MySQL - (2006-03-31) 
Using a MySQL database from Perl - (2006-03-13)
Some other Articles
Catching the fishes first?On this day ... one PHP script with three usesAway to train - but still around by video for Melksham meetingsStepping stones - early coding, and writing re-usable code quicklyMySQL, MySQLi, PDO or something else - how best to talk to databases from PHPYour PHP website - how to factor and refactor to reduce growing painsReading and using emails including enclosures on your web server.Which or ATOC - who reads train fares right?Why would you want to use a Perl hash?A threat in the post? Poor marketing practise from Smiletrain?