Data Mappers and DTOs
Learn to map data between internal Entities and external data structures (DTOs) for database or API interactions.
Mapping Data: Why We Need It
In Clean Architecture, your core business logic (Entities and Use Cases) should be independent of external details like databases or web frameworks.
But how do your internal data structures communicate with the outside world? This is where Data Mappers and Data Transfer Objects (DTOs) come in.
Entities vs. External Data
Your Entities contain crucial business rules and are designed for your domain logic. They often have methods and complex relationships.
Exposing these entities directly to external layers (like a database or an API) can lead to:
- Tight Coupling: Changes in your database or API might force changes in your core entities.
- Security Risks: You might expose sensitive internal data.
- Data Shape Mismatch: External systems often need data in a different format than your internal domain model.