I think the general idea to be able to test bits and pieces of the logic. With an ORM like ActiveRecord, Sequel, or SQLAlchemy, you can split up a much larger q

I think the general idea to be able to test bits and pieces of the logic. With an ORM like ActiveRecord, Sequel, or SQLAlchemy, you can split up a much larger query into multiple functions and then test each individual function. It makes it a lot easier to reason about future changes. I don't know if I agree with a "Query Object" - I don't instantiate objects that much these days, but it's nice to put that logic into a different file than, say, your model or controller.