from sqlalchemy import Column, Integer, String, DateTime, JSON, ForeignKey from sqlalchemy.orm import relationship from sqlalchemy.sql import func from database import Base class MindMap(Base): __tablename__ = "mind_maps" id = Column(Integer, primary_key=True, index=True) user_id = Column(Integer, ForeignKey("users.id"), nullable=False, index=True) title = Column(String(200), nullable=False) subject = Column(String(50), default="综合") nodes = Column(JSON, default=list) created_at = Column(DateTime, server_default=func.now()) updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now()) author = relationship("User", back_populates="mind_maps")