类在SQLalchemy中没有名为“x”的映射列

Question

我在Django环境中使用SQLAlchemy（v1.2.11），所以我可以在Firebird数据库（公司的ERP使用）和我在Django开发的intranet之间建立一些映射。我使用声明性的作为映射，因为instrospection不起作用。在

fire5.1版本的查询也没有太大的帮助（我只能选择其中一个版本的查询）。在

我想做的一件事是让用户（在某些特定情况下）创建报告并与Firebird数据交互，在我的Django项目中创建相关记录。在

但是，在一个特定的映射中，我得到

Class <class 'SalesDetail'> does not have a mapped column named 'seller_id'

当查询准备好并使用关系时。让我抓狂的是，我还在这个类ProductSells中映射另外两个关系，它们非常相似，而且工作良好。在

首先，与我要查询的表（SalesDetail）相关的基本映射：

^{pr2}$

下面是我想问的关系：

class SalesDetail(Base):
    __tablename__ = 'sales_detail'

    sale_id = Column(Integer, ForeignKey('sales.sale_id'))
    sale_company = Column(Integer, ForeignKey('sales.company_id'))
    sale_control = Column('sale_control', Integer)
    product_code = Column(Integer, ForeignKey('products.product_code'))
    product_company = Column(Integer, ForeignKey('products.company_id'))
    seller_id = (Integer, ForeignKey('sellers.seller_id'))
    seller_company = (Integer, ForeignKey('sellers.company_id'))
    qty = Column('qty', Integer)
    discount = Column('discount', Numeric)

    seller = relationship(
        'Sellers',
        primaryjoin=(
            'and_('
            'SalesDetail.seller_id == Sellers.seller_id, '
            'SalesDetail.seller_company == Sellers.company_id'
            ')'
        ),
        innerjoin=True
    )

    product = relationship(
        'Products',
        primaryjoin=(
            'and_('
            'SalesDetail.product_code == Products.product_code, '
            'SalesDetail.product_company == Products.company_id'
            ')'
        ),
        innerjoin=True
    )

    sale = relationship(
        'Sales',
        primaryjoin=(
            'and_('
            'SalesDetail.sale_id == Sales.sale_id, '
            'SalesDetail.sale_company == Sales.company_id'
            ')'
        ),
        innerjoin=True
    )

    __mapper_args__ = {
        'primary_key': [sale_id, sale_company, sale_control],
    }

我的问题是：

query = self.session.query(
            SalesDetail.sale_id,
            Sales.sale_date,
            Sellers.seller_id,
            Products.product_code,
            Products.name,
            SalesDetail.qty,
        ).join(
            SalesDetail.sale,
            SalesDetail.product,
            SalesDetail.seller,
            Products.brand
        )

        query = query.filter(and_(
            Sales.sale_date >= start_date,
            Sales.sale_date <= end_date,
            Sales.status != 'CAN',
            Sales.company_id == self.company.id,
            Products.product_type == 'R',
            Brands.name.in_(brands),
            Sellers.seller_id > 1001,
            Sellers.seller_id < 9000
        )).order_by(
            Sellers.seller_id,
            Sales.sale_date,
            Sales.sale_control
        )

        res = query.all()

这引发了一个例外：

Class <class 'src.erp.models.SalesDetail'> does not have a mapped column named 'seller_id'

但是，如果我将SalesDetail更改为：

class SalesDetail(Base):
    __tablename__ = 'sales_detail'

    sale_id = Column(Integer, ForeignKey('sales.sale_id'))
    sale_company = Column(Integer, ForeignKey('sales.company_id'))
    sale_control = Column('sale_control', Integer)
    product_code = Column(Integer, ForeignKey('products.product_code'))
    product_company = Column(Integer, ForeignKey('products.company_id'))
    seller_id = Column('seller_id', Integer)
    seller_company = ('company_id', Integer)
    qty = Column('qty', Integer)
    discount = Column('discount', Numeric)

如果我从SalesDetail中删除属性seller，并更改查询：

query = self.session.query(
            SalesDetail.sale_id,
            Sales.sale_date,
            SalesDetail.seller_id,
            Products.product_code,
            Products.name,
            SalesDetail.qty,
        ).join(
            SalesDetail.sale,
            SalesDetail.product,
            Products.brand
        )

一切正常。有趣的是：我认为从SalesDetail到Sales和Products的关系是完全相同的，使用一个复合外键，它工作得很好。所以复合键和我的Firebird数据库似乎没有问题。在

当我设置断点时，我可以看到SQLAlchemy在Mapper类（SQLAlchemy/orm）中将seller_id和seller_company识别为声明字段/映射器.py). 在

SQLAlchemy代码中的堆栈跟踪如下：

File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/query.py", line 2136, in join
    from_joinpoint=from_joinpoint)
File "<string>", line 2, in _join
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/base.py", line 201, in generate
    fn(self, *args[1:], **kw)
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/query.py", line 2243, in _join
    right_entity = onclause.property.mapper
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/util/langhelpers.py", line 767, in __get__
    obj.__dict__[self.__name__] = result = self.fget(obj)
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/attributes.py", line 215, in property
    return self.comparator.property
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/util/langhelpers.py", line 767, in __get__
    obj.__dict__[self.__name__] = result = self.fget(obj)
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/relationships.py", line 1354, in property
    mapperlib.Mapper._configure_all()
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/mapper.py", line 1276, in _configure_all
    configure_mappers()
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/mapper.py", line 3033, in configure_mappers
    mapper._post_configure_properties()
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/mapper.py", line 1832, in _post_configure_properties
    prop.init()
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/interfaces.py", line 183, in init
    self.do_init()
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/relationships.py", line 1655, in do_init
    self._process_dependent_arguments()
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/orm/relationships.py", line 1680, in _process_dependent_arguments
    setattr(self, attr, attr_value())
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/ext/declarative/clsregistry.py", line 281, in __call__
    x = eval(self.arg, globals(), self._dict)
File "<string>", line 1, in <module>
File "/home/alexandre/.virtualenvs/intranet-salao/lib/python3.5/site-packages/sqlalchemy/ext/declarative/clsregistry.py", line 213, in __getattr__
    % (self.cls, key))
sqlalchemy.exc.InvalidRequestError: Class <class 'src.erp.models.SalesDetail'> does not have a mapped column named 'seller_id'

Answer 1

这是一个有点打字错误，但偶尔会出现一些东西。错误消息将准确地告诉您出了什么问题：

seller_id = (Integer, ForeignKey('sellers.seller_id'))

创建元组，而不是Column。你是说

^{pr2}$

同样的错误出现在seller_company中。在