WCF DataContracts and underlying data structures

Question

I am wondering what makes sense in relation to what objects to expose through a WCF service - should I add WCF Serialization specifications to my business entities or should I i

Answer 1

I typically don't expose my business/data entities across the wire since I like to adhere to the single responsibility principle (srp). To explain, the data entities were created to map to the underlying relational (db) model. So the only reason they should "change", is because of a change to the relational model, that's it.

The moment you expose such entities so they can cross the wire, then they're serving two purposes. It may seem like overkill, but it keeps things cleaner and transparent...which yields for a simpler design.