data-access

To choose the right persistence pattern, you evaluate domain boundaries and storage needs against criteria for Repository, Unit of Work, Data Mapper, and Active Record. This prevents infrastructure logic from leaking into your business domain code.

The difference lies in separation level: Active Record tightly couples domain models to storage, while Data Mapper isolates them entirely. Repository abstracts collections, and Unit of Work coordinates transactional writes, guiding distinct persistence strategies.

You should use the Active Record pattern when domain boundaries are simple and tightly align with storage tables, whereas the Repository pattern is preferred when you need stricter infrastructure separation and complex domain querying.

You apply persistence patterns like Repository or Data Mapper to isolate domain logic, allowing tests to run against realistic databases without tightly coupling business rules to specific storage infrastructure.

The best way to refactor domain models intertwined with storage is to analyze the existing module and select an appropriate pattern, such as Data Mapper or Unit of Work, to separate business logic from infrastructure before adding storage integration.