Designing aggregates and entities
It is very important to design your entities and aggregate boundaries since the rest of the solution components will be based on that design. In this section, we will first understand what an aggregate is. Then we will see some key principles of an aggregate design. Finally, I will introduce some explicit rules and code examples to understand how we should implement aggregates.
What is an aggregate root?
An aggregate is a cluster of objects bound together by an aggregate root object. The aggregate root object is responsible for implementing the business rules and constraints related to the aggregate, keeping the aggregate objects in a valid state and preserving the data integrity. The aggregate root and the related objects have methods to achieve that responsibility.
The Event aggregate shown in the following figure is a good example of aggregates:
Figure 10.1 – The Event aggregate
The examples in this chapter...
