import uuid from datetime import datetime from sqlalchemy import Column, String, DateTime from app.database import Base class BaseModel(Base): __abstract__ = True id = Column(String(36), primary_key=True, default=lambda: str(uuid.uuid4())) created_at = Column(DateTime, default=datetime.utcnow, nullable=False) updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow, nullable=False)