by Kieran Mathieson

PHP applications use various technologies, like HTML, relational databases (RDB), JavaScript, object-oriented programming (OOP), and so on. Most of them work well together. For instance, PHP code can easily write JavaScript, JavaScript can use a browser's document object model (DOM) to change HTML, etc.

OOP and RDB don't fit together quite as well. When programmers write code mapping PHP classes to RDB tables, they need to make sure the classes do not become too dependent on each other. Otherwise, changes in one class will require changes in others, raising development and maintenance costs. If software changes become too expensive and take too much time, applications will restrict business innovation, rather than enabling it.

This paper offers a practical solution to the object-relational problem in PHP. "Practical" means an approach meeting the constraints that usually apply in application development:

We'll use the term "application utility tasks" to refer to the things listed in the last bullet point. They often consume significant resources, sometimes more than the rest of the application. Carefully managing application utility tasks is important to application stability and performance. It's usually best to start building them in at the very beginning of a project, rather than try to add them later.

This paper assumes you're familiar with PHP, OOP, and relational databases. If you're not, you might want to consult these tutorials: