When using Object Relational Mapping, you typically have two options, using the Active Record Pattern or using the Repository Pattern.
Active Record Pattern:
Entity e = Entity.create();
e.setSomeField("abc");
e.save();
Repository Pattern:
Entity e = Entity.create();
e.setSomeField("abc");
repository.save(e);
Both have their pros and cons - active record, you have fewer classes, but you mix your business logic into your data model, repository, you have a lot more classes, but your data model is separate from your business logic.
Which do you choose and why?
For some pointers, see:
Jorge Riva
Why not both?
Entity e = Entity.create(new Repository()); -> or inject IRepository e.setSomeField("abc"); e.save(); -> inside _repository.Save();