[Zope] ZODB or MySQL for form data?

I'm coming to Zope from PHP where my database is MySQL. However I am wanting to move to Zope and am trying to learn the correct way of working in this platform. I know that I can connect to MySQL from Zope but from what I read it appears that the use of this feature is recommended only if one is wanting to use an existing database. Since I am starting a new Zope application, and will be creating new data files, is it better to use MySQL or ZODB to handle form data? I would really appreciate hearing from experienced Zope users on this matter. Paul