The Vertabelo site has posted a tutorial that gives you an "under the hood" view of ORMs and what they're doing in the background to help make accessing your database information easier.

It often happens that if something is loved, it is also hated with the same power. The idea of object relational mapping fits into this concept perfectly. You will definitely come across many opposite points and fierce discussions as well as unwavering advocates and haters. So if you have ever asked whether to use ORM or not, the answer “it depends” will not be enough.

They start with a definition of an ORM to get everyone on the same page, highlighting how they represent database contents and what some of the benefits are in using them. From there the article talks about the importance of good SQL and a few common dangers in using an ORM and not knowing SQL. Then the article gets into how ORMs work and some of the common design patterns they can implement. It lists some of the more popular ORMs (for Python, Java and PHP) and covers some of the main disadvantages to their use. The article ends with examples of some of the libraries mentioned, highlighting the Propel ORM for the PHP world.

In a new post to his blog Brandon Savage takes a quick loook at hos he integrated Propel into a Zend Framework app he'd built to replace an older site.

I wanted to use Zend Framework to practice on it, and to learn things I hadn't yet learned since I had yet to put an application into production; however, I didn't have any desire to rewrite my model, which was done in Propel. Propel has two things going for it already: the first is that Propel includes its own autoloader, meaning that I didn't have to try and force Propel into Zend Framework's file system structure. The second is that Propel is designed to let you put it's files anywhere you want with ease, so long as you update your include path properly.

He walks you through the process he followed to get things up and running - placement of the Propel libraries, working with the Propel configuration file and some pathing problems he finally figured out (by putting a model include directory into the path too).

In a recent post to his blog Brandon Savage evaluates Propel (ORM) to see what it has to offer him and his applications.

I’ve liked Propel ever since I started working with it in the middle of last year; I personally find it easier and more fun to use than Doctrine or other ORMs available today. I was excited to see recently that Propel's development team had released Propel 1.5 as a beta, with a launch of the new features to come soon.

He points out two of the newer features that he particularly likes - collections and on-demand hydration and model queries. The first lets you hydrate the results fetched as you need them instead of all at once and the second does away with some of the issues that came up with making Criteria objects. You can find out more about these and other new features on the Propel "What's New" page.

Since the Symfony framework project has such tight integration with both the Propel and Doctrine ORM layers, they thought they'd share some statistics on the usage of both as mapped through the stats from their Jobeet tutorial.

As for any Open-Source community, it's not easy to find metrics that tell you what people use and how they use it. You can measure the number of tickets for a specific feature, count the number of people asking for help on Propel or Doctrine. But for the Propel vs Doctrine question, we have two more reliable metrics.

As is shown in this graph of the total Jobeet traffic in 2009, Doctrine is winning by a long shot. That's not to say that you can't still use Propel is that's what you and your application are using, this is just showing the overall popularity of each of the ORMs.

Following some issues with the Phing and Propel subversion repositories for Symfony, Fabien Potencier has made a few changes to aid in their future stability.

The Phing and Propel Subversion repositories have suffered from long downtime periods quite often recently (last one was today). It is quite annoying as when it happens, you cannot easily update your symfony repositories, let alone the checkout of a symfony branch. To make things worse, the Doctrine repository also had some problems recently. A lot of symfony users are quite upset by the situation, myself being the first one.

The solution - create some mirrors to provide more than one source to fetch the latest checkouts from. Here's the list of the new resources: Phing mirror, Propel mirror, Doctrine mirror.

Jani Hartikainen takes a look at two of the major PHP ORM libraries in this new post - Propel and Doctrine.

The best PHP ORM libraries, Doctrine and Propel. Last year I compared them to each other, and now it's time to get a fresh look at how they have advanced in about a year - Is Doctrine still the better of the two? This time, I'll also look at the features of each in more depth.

He goes through some of the features (basic and advanced), how easy they are to use and their connections to the database. His personal preference? Doctrine works better for his needs.

Tony Bibbs has a reminder about a webinar he will be presenting on Propel as a part of the php|architect free webcast series leading up to this year's php|tek conference.

This is just a friendly reminder that this Friday, March 27th from 12pm-1pm CST I will be giving a webinar on using Propel, an object relational mapper (ORM). This webinar is just one of a series being sponsored by php|architect. The webinar will focus on the basics of installing and using Propel as well as one or two more advanced topics.

You can register for this webinar here and check out some of the other upcoming talks on this page on the MTA conference website. Other sessions include PHP & Flash, application security and working with Zend Framework/Dojo.

The symfony blog has posted an update on the status of their "Practical symfony" book - the Doctrine version has officially been released!

Last week, we released the "Practical symfony" paper book (380 pages). The "Practical symfony" book is based on the Jobeet tutorial, and is the best book to read to get you started on symfony 1.2. It describes everything you need to know to develop professional web applications with the symfony framework.

As for the Propel edition, we have worked hard to update the Doctrine edition as fast as possible. The Doctrine version is now up to date and thanks to Jon work, you can even enjoy a tagged repository for each day of the tutorial.

The book works through the Jobeet tutorial series they posted at the end of 2008 to create a complete job posting website with the symfony framework.

On the Symfony blog today there's a new post from Fabien Potencier about a new book that's just been released and might be of interest to those wanting to get into the framework - Practical Symfony.

Two years after the publishing of "The Definitive Guide to symfony" book, I am happy to announce that the Jobeet tutorial is now available as a printed book: "Practical symfony". During the last two weeks, I have updated and enhanced the Jobeet tutorial based on the feedback from the community. I have also updated the screenshots to reflect the new Jobeet design. The "Practical symfony" book is the printed version of this tutorial and as such covers the symfony 1.2 version.

The Jobeet tutorial was their 2008 "advent" piece that created a job posting website from scratch with each day focusing on a different aspect of the application. There are two versions of the book (Propel and Doctrine) but for now, only the Propel version can be purchased over on lulu.com.

Symfony developers out there will be happy to know that, since the release of symfony 1.1, writing unit tests for your models has been made even easier.

Writing unit tests for your Propel or Doctrine model is much more easier as of symfony 1.1. In this tutorial, you will learn some great tips and best practices to write better tests for your models.

The tutorial walks you through the creating of a simple test - evaluating a few criteria for the database contents. The entire thing is contained inside of YML files and is easily run via the sfConfig and integrated Propel functionality.