Coupling and Responsibilities of DAO and Entity Model

I've spent the lunch hour reading:

• Difference between Active Record and DAO?


• DAO pattern and model objects


• Difference between Data Access Layer and Model in MVC


• DAO classes with CRUD methods VS. DAO classes with entity-specific methods

While these have helped me understand the differences between the design patterns, I am no closer to answering my implementation questions.

Assuming I have an Entity Model (User) and DAO (UserDAO), the following is still unclear:

• How are the Entity Model and DAO coupled? If dependency injection, then what object binds them together?


• Should the DAO only be accessed through the model, or can other objects access it directly (e.g. from Controller under MVC).


• In the same vein, should entity specific methods (e.g. getActiveUsers) be on the model or DAO.

I know this topic is broad, and open for a debate, I would appreciate supported answers.