What to do with queries which don´t have a representation in a domain model?

Question

This is not specific to any language, it´s just about best practices. I am using JPA/Hibernate (but it could be any other ORM solution) and I would like to know how do you guys deal with this situation: Let´s suppose that you have a query returning something that is not represented by any of your domain classes. Do you create a specific class to represent that specific query? Do you return the query in some other kind of object (array, map...) Some other solutions? I would like to know about your experiences and best practices.

P.S. Actually I am creating specific objetcs for specific queries.

Answer 1

We have a situation that sounds similar to yours.

We use separate objects for reporting data that spans several domain objects. Our convention is that these will be backed by a view in the database, so we have come to call them view objects. We generally use them for summarising complex data into a flat format.