Supporting ad-hoc queries in a multi-tiered application

Question

Is there a standard design pattern or approach that will support ad hoc queries in a multi-tiered application?

Some motivation for this question: In my current project, we are using the IRepository<> pattern extensively in the middle tier. The version of IRepository<> that we're using has a FilterBy() method that takes in an Expression<> in an attempt to support arbitrary queries. But if the Expression<> is composed (say) at the ViewModel level, it will be expressed in terms of DTOs (Data Transfer Objects)....

How do we avoid either exposing the UI to database-specific details or doing a "GetAll()" at the database level, wrapping everything as it passes up through the layers, only to discard 90% of it at the DTO/ViewModel layer?

Thanks, Jim

Answer 1

This question is answered by a separate post: Generic vs. Specialized Repositories