How to implemented this using Repository Pattern (or something more appropriate)?

I have a repository called: IChocolateRepository

It derives from 开发者_开发知识库a generic repository interface IRepository<> which defines basic repository functions (FindAll, Delete, Add, etc.)

Now, I need to write a piece of code which will go and delete 'all chocolates from the database with expiry data before a supplied date' (assuming that ExpiryDate is a non-nullable property on the Chocolate model class.)

Does this belong in the repository?

Also, how would a sample implementation look like? (I am using EF CTP5)

I don't think so.

This does not belong in the Repository but in a class that operates the Transactions using these Repositories.

Unless this is just too simple application where avoiding a separate layer to avoid complexity would be much better.

If you already have Remove(T item) method in base interface then it won't hurt if you add Remove(Predicate<'T'> condition) to satisfy your needs.

Therefore instead of deleting one particular item you can have a very generic interface to delete everything that satisfies the given predicate.

I had a small project (FYP for university degree) and due to time constraints and that i didn't know better I added my more complex data methods to the repository, hard coded.

Personally I would use Andrei Taptunov idea with predicates, so that data access code is contained within the repository class. I have seen transactions written in a domain driven design book, which work like predicates anyway. A transaction records what you want to achieve and a repository works on that request.