"""SQLAlchemy base model.""" from datetime import datetime from sqlalchemy import func from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column class Base(DeclarativeBase): """Base class for all models.""" pass class TimestampMixin: """Mixin for created_at and updated_at timestamps.""" created_at: Mapped[datetime] = mapped_column(default=func.now()) updated_at: Mapped[datetime] = mapped_column(default=func.now(), onupdate=func.now())