One of the side effects of working with database driven software is that you eventually find yourself needing to pull in large amounts of information from old and terrible systems. When talking to your counterparts on the other side of the line (the inter-company line, that is), you will invariably be told that you will only receive your data in one of a few straight forward formats. What follows is a small extension to Python's CSV object which streamlines the process of coding these data transformations.
All too often, while running the PHP forum on The Scripts, I see students working who are completely ignorant of the security concerns prevalent with the systems that they build. Worse, when alerted to the potential dangers associated with poor programming practices, these coders let loose a variety of excuses why their application doesn't need to implement a security policy. Ranging from "this is a low traffic/internal site" to "I'm doing this as a project for school, so security really isn't an issue." In my eyes all explanations are equally irrelevant. As leaders of the forums, my colleagues and I daily battle assertions about the validity of these concerns.
The goal of this tutorial is to design a Data Abstraction Layer (DAL) in PHP, that will allow us to ignore the intricacies of MySQL and focus our attention on our Application Layer and Business Logic. Hopefully, by the end of this guide, you will have a working DAL and learn a little about PHP, MySQL, and Object-Oriented design in the process.