flask实现软删除

class Goods(Base):
    id = Column(Integer, primary_key=True, autoincrement=True, comment='id')
    flag = Column(JSON)
    sort = Column(Integer)
    create_time = Column(TIMESTAMP(True), server_default=func.now())
    update_time = Column(TIMESTAMP(True), nullable=False, server_default=func.now())
    delete_time = Column(TIMESTAMP(True))

给Goods类统计delete_time属性， 如果为None即正式，有时间就是别删除的了，

改写sqlalchemy得filter_by方法。

class Query(BaseQuery):
    def filter_by(self, **kwargs):
        if hasattr(self.statement.columns, 'delete_time'):
            if 'delete_time' not in kwargs.keys():
                kwargs['delete_time'] = None
        return super(Query, self).filter_by(**kwargs)

用hasattr函数判断self.statement.columns是否存在delete_time这个属性，如果存在添加一条kwargs['delete_time'] = None的查询条件。