Integrate with Existdb

I am new to this orbeon xform. I have created a sample form by taking direction from bookcast application. My requirement is integrating orbeon form with PHP cms. So we planned to save the submitted data to exist db (not in orbeon embed exist) and at end of day take all submitted data from the exist db and send to cms database. So sombody could help me the approach for the same, or let me know do i have any other method/approach for the same. We will install orbeon seperately, not integrating with cms. but we need to get daily submitted data from exist db and pass to cms(postgresql db).