In this latest post to his site Stefan Koopmanschap shares a solution he's found to migrating data with Doctrine2 from an existing structure.

A project that I'm working on right now required me to migrate data from the existing database to the new database and database structure. Since the application is built on top of Symfony2, I decided to write a Command that would take care of the migration. I ran into an issue though: Doctrine2 insisted on creating new IDs where I wanted to keep the old one. The solution turned out to be really simple.

The actual code for the Command is only a few lines long - it just turns off the "AUTO" strategy for each of your entities, making it ignore any IDs you have set on the entity already.