In a new post today, Martynas Jusevicius shows how to combine a little SQL magic with the Propel framework to fins the distance between two places:

Eventually the simple distance formula that I have blogged about turned out to be too inaccurate, even for locations within city bounds. I needed to use a formula to calculate great-circle distance which takes into account that the Earth is a sphere.

He includes the SQL to pull the data in the right format and the PHP code (using Propel) to reproduce it without having to write it by hand (complete with the bind variables to help with security and consistency).

In his latest entry, Alexander Netkachev explains how to install the Propel object persistence layer and it's needed packages into your PHP application.

Object persistence layer provides the developers with the API that allows them to operate with data of the application in object-oriented manner. The developers can use known OOP methods for searching for and restoring the objects from the database. Something like this you can find on the main page of the Propel project and in the Wikipedia article about ORM technology.

These enthusiastic words roused my interest in the technology and I promised myself I would spend some time on testing a software for generating object persistence classes. And I ready to try the Propel library, because it is used by the Symphony framework, which I plan to test in a couple of weeks.

He starts with a little background information about why he's chosen to go with Propel and the process he followed to get things up and running smoothly. He links to the software you'll need (Propel, Creole, and Phing) and gives the install structure and environment variables you'll need to set. Finally, he gives an example .bat file to help perform the install automatically, reducing the problems that could happen when done manually.