SQLAlchemy ORM for Python Developers

What the Article Covers

• Defining models with Mapped type annotations
• One-to-many relationships with relationship() and back_populates
• Cascade delete with cascade="all, delete-orphan"
• Managing sessions with a context manager
• Inserting related records in a single transaction
• Filtering, joining, updating, and deleting rows
• Avoiding the N+1 query problem with selectinload

All examples use SQLite, which requires no setup beyond installing SQLAlchemy:

pip install sqlalchemy