sqlalchemy的Mixin类中字段重命名

问题：因为是项目从mysql更换到达梦dm8数据库，同时数据库字段也需要更换为国标要求，使用column_property会有警告，改用synonym，但在Mixin类中会报错：sqlalchemy.exc.InvalidRequestError: Mapper properties (i.e. deferred,column_property(), relationship(), etc.) must be declared as @declared_attr callables on declarative mixin classes. For dataclass field() objects, use a lambda

解决：根据提示使用@declared_attr进行装饰

方法：

from sqlalchemy.ext.declarative import declarative_base, declared_attr
from sqlalchemy.orm import synonym
from db.session import engine
from sqlalchemy import (
    Column, Integer, String, DateTime)

Base = declarative_base()
Base.metadata.create_all(bind=engine)

class BaseMixin(object):
    BH = Column(Integer, primary_key=True, autoincrement=True)
    SFSC = Column(Integer, server_default='0')
    CJZ = Column(Integer)
    CJSJ = Column(DateTime)
    GXZ = Column(Integer)
    GXSJ = Column(DateTime)
    SCZ = Column(Integer)
    SCSJ = Column(DateTime)
    QTXX = Column(String(1024))

    @declared_attr
    def id(self):
        return synonym('BH')
    @declared_attr
    def is_delete(self):
        return synonym('SFSC')
    @declared_attr
    def create_id(self):
        return synonym('CJZ')
    @declared_attr
    def create_time(self):
        return synonym('CJSJ')
    @declared_attr
    def update_id(self):
        return synonym('GXZ')
    @declared_attr
    def update_time(self):
        return synonym('GXSJ')
    @declared_attr
    def delete_id(self):
        return synonym('SCZ')
    @declared_attr
    def delete_time(self):
        return synonym('SCSJ')
    @declared_attr
    def info(self):
        return synonym('QTXX')

参考：

https://www.coder.work/article/366125