Implementing Domain-Driven Design

Unique Identity

In the early stages of designing an Entity, we purposely focus only on those primary attributes and behaviors that are central to its unique identity, as well as those useful for querying it, and we purposely ignore all other attributes and behaviors until we settle on the primary ones.

Rather than focusing on the attributes or even the behavior, strip the Entity object’s definition down to the most intrinsic characteristics, particularly those that identify it or are commonly used to find or match it. Add only behavior that is essential to the concept and attributes that are required by that behavior. [Evans, p. 93]

So that’s what we’ll do first. Having a range of available options for implementing identity is really important, ...