What are the advantages and disadvantages of using the Repository pattern compared to using ORM for data access?

Advantages of the Repository pattern:

• Data access abstraction: hides database details, simplifying testing and maintenance.
• Centralizes data access logic, making it easier to change the data source without affecting business logic.
• Improves code readability and structure by separating business logic and data access layer.

Disadvantages:

• Additional abstraction layer can complicate architecture and increase code volume.
• When using powerful ORMs that already provide rich APIs, the Repository pattern may duplicate functionality.
• Requires extra time for design and maintenance.

Using ORM:

• ORM (Object-Relational Mapping) directly links objects to database tables, simplifying CRUD operations.
• Enables rapid development without writing SQL.

Comparison:

• Repository provides a cleaner architecture and flexibility, especially in large projects.
• ORM is convenient for quick prototyping and simple applications.

Example of a simple Repository in Python using SQLAlchemy (ORM):

class UserRepository:
    def __init__(self, session):
        self.session = session

    def get_by_id(self, user_id):
        return self.session.query(User).filter(User.id == user_id).first()

    def add(self, user):
        self.session.add(user)
        self.session.commit()

Here, the Repository encapsulates ORM calls, allowing future replacement of ORM or modification of access logic without changing business logic.