Data Mapper
Data Mapper is a design pattern in software development that separates the in-memory object representation from the database persistence logic. It acts as an intermediary layer that maps data between objects in an application and a database, handling the conversion and transfer without coupling the domain objects to the database schema. This pattern is commonly used in object-relational mapping (ORM) systems to abstract database interactions and promote cleaner, more maintainable code.
Developers should learn and use Data Mapper when building applications that require a clear separation between business logic and data persistence, such as in enterprise systems or complex domain-driven designs. It is particularly useful for scenarios where database schemas change frequently or when multiple data sources need to be integrated, as it decouples the domain model from storage details, improving testability and flexibility. For example, in web applications using ORM tools like Hibernate or Doctrine, Data Mapper helps manage database operations without polluting domain objects with SQL queries.