Repository, Entity objects and Domain Objects

Question

In my Repositories, I am making assignments to my domain objects from the Linq Entity queries. I then have a service layer to act on these object returned from repositories.

Should my Domain objects be in the repository like this? Or should my repositories be restricted to the Entities and Data Access, and instead have my service layer make assignments to the domain objects?

Doing all assignments in Repository seems easier, but now the distinction between my database and domain objects is not apparent. What is proper practice here? tia

Answer 1

IMO if the app is relativly simple and you cant imagine ripping out the Data access go ahead and make the asignments in the Repository. But if you think the app will get more complicated in the future or that you may want to change the data access keep this functionality out of the repositories.

I have done apps with assignement in the repositories and other in the service layer and yet another one i had a seperate conversion layer (it was not a one on one conversion and the objects were complex).

One thing to remember about best practices, There there to help, if it makes thing more dificult then dont use it.

Answer 2

I used to not like it. But now usually never look back. Basically the thing is that if you need to change to an external datasource that is structured different, you can set up a new mapping along with the implementation of the repository code and be done with it.

It is about data mapping. Check this link: http://www.martinfowler.com/eaaCatalog/repository.html

Also check this related question: http://stackoverflow.com/questions/524603/irepository-confusion-on-objects-returned. I have used a similar mapper, but have made it operated at the IQueryable level, which have made able to do some pretty interesting stuff while working with the Domain Object after the mapping.