title: Doctrine2: proper organisation of CRUD operations.
body: <p>Need some advice on how to organise CRUD operations for model using doctrine2. 
  I use yaml mapping file for table definition. Auto generate model classes, proxies and custom repository classes. In my entity repository classes i define methods for complex SQl, DQL. But i'm not sure where i must put Create, Update and Delete operations? In repository class? In model class? </p>