http://symfony.com/doc/current/doctrine/reverse_engineering.html - Wszystko opisane w dokumentacji. Jak nie zaskoczy to albo baza źle zaprojektowana, albo doctrine nie daje rady i trzeba będzie ręcznie budować encje.
Reverse Engineering is not always working perfectly depending on special cases. It will only detect Many-To-One relations (even if they are One-To-One) and will try to create entities from Many-To-Many tables. It also has problems with naming of foreign keys that have multiple column names. Any Reverse Engineered Database-Schema needs considerable manual work to become a useful domain model.