在单个SQLAlchemy验证器中访问多个属性

from sqlalchemy import Column, Integer, String
from sqlalchemy.orm import validates
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

class User(Base):
    __tablename__ = 'users'

    id = Column(Integer, primary_key=True)
    first_name = Column(String)
    last_name = Column(String)

    @validates('last_name')
    def validate_last_name(self, key, last_name):
        # 访问多个属性的值
        if self.first_name and last_name:
            full_name = f"{self.first_name} {last_name}"
            # 自定义验证逻辑
            if len(full_name) < 5:
                raise ValueError("Full name must be at least 5 characters long.")
        return last_name