repository-pattern

I'm implementing the repository pattern as part of an ASP.NET MVC site. Most examples I've seen of repositories are fairly simple. For example here's a typical abstract repository interface. public interface IRepository<TEntity> { IQueryable<TEntity> All(); TEntity FindBy(int id); TEntity FindBy(Expression<Func<TEntity, bool>> expression); IQueryable<TEntity> FilterBy(Expression<Func<TEntity, bool>> expression); bool Add(TEntity entity); bool Update(TEntity entity); bool Delete(TEntity entity): } It's clear to me how you would use a repository like this to add, update, delete, or get entities

I'm new to the Repository Pattern and after doing a lot of reading on the web I have a rough understanding of what is going on, but there seems to be a conflict of ideas. One is what the IRepository should return. I would like to deal in ONLY Pocos so I would have an IRepository implementation for every aggregate root, like so: public class OrangeRepository: IOrangeRepository { public Orange GetOrange(IOrangeCriteria criteria); } where IOrangeCriteria takes a number of arguments specific to finding an Orange. The other thing I have is a number of data back-ends - this is why I got into this

I've been reading the book Pro ASP NET MVC Framework and I'm getting really confused with a lot of things. I've been trying to do some research but I'm finding that with so many different approaches and concepts being thrown at me, it's just making things worse. So I have a few questions: I know MVC is supposed to split the functionality into three main things: Model -> Controller -> View. Is the MVC a different approach than the three-tier architecture? Or am I still supposed to be thinking of creating a Data Access Layer and a Business Logic Layer in my project? What exactly are Repositories