13 Nov 2023
Entities: In DDD, an entity is an object that represents a real-world thing. Entities are objects that have a unique identity and can change over time. Entities are typically persisted in a database, but they can also be stored in memory or other data stores.
For example, a Product entity might be defined by its product ID. This ID is unique and will not change even if the product's name, price, or other attributes change.
Sure, here are the characteristics of entities in Domain-Driven Design (DDD) outlined in points:
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Unique Identity: Entities possess a distinct and unique identity that sets them apart from other objects within the system. This identity remains constant throughout their lifecycle.
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Changeable State: They can undergo changes in their internal state over time, reflecting the dynamic nature of real-world objects they represent.
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Lifecycle Management: Entities follow a lifecycle that includes creation, modification, and potentially deletion, mirroring the real-world lifecycle of the objects they model.
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Behavior Encapsulation: Entities encapsulate not just data but also the behavior associated with the specific domain they represent. This behavior includes methods or functions that reflect the actions and operations related to the entity. For example, a
Productentity might have behavior associated with adding it to a cart, checking out with the product, and returning the product. -
Persistence: Entities are often persisted in a database or other data stores to maintain their state and ensure their availability across different sessions or parts of the application.
Here are some examples of entities in a DDD application:
- Customer
- Order
- Product
- Account
- Shipment
- Employee
- Vehicle
