Hibernate support has been introduced in CDB 4.1. If you are interested in SQL or POJO-based generation, stick to the previous version of CDB and refer to the CDB 4.0 workshop PDF, which is also located in General Docs.
I’ve recorded screencasts. The first screencast is about supporting entities in CDB 4.1. It starts from the finished application and then I explain how it was generated. The second one is about using hierarchical collections with entities.