My models look like this:
class Company(DB_BASE):
__tablename__ = 'Company'
id = Column(Integer, primary_key=True, index=True)
...
products = relationship('Product', secondary=Company_Products, backref='Company')
class Product(DB_BASE):
__tablename__ = 'Product'
id = Column(Integer, primary_key=True, index=True)
...
companies = relationship('Company', secondary=Company_Products, backref='Product')
This is my association table
Company_Products = Table(
'Company_Products',
DB_BASE.metadata,
Column('id', Integer, primary_key=True),
Column('company_id', Integer, ForeignKey('Company.id')),
Column('product_id', Integer, ForeignKey('Product.id')),
Column('quantity', Integer, default=0),
Column('price_per_unit', Integer, default=0),
)
And this is how I'm querying the association table.
company_product = db.query(Company_Products).filter_by(product_id=id, company_id=user.company_id).first()
company_product.quantity = data.data['quantity']
company_product.price = data.data['price']
After creating the many-to-many relationship between a Company and a Product, I would like to modify the relationship extra data, quantity and price_per_unit in this instance. After querying the association object, modifying any attribute yields:
AttributeError: can't set attribute 'quantity'
Go on with my question, the solution that ended up working for me is to create a new model and use it to simulate a association table a bit.
class Company_Products(DB_BASE): __tablename__ = 'Company_Products' id = Column(Integer, primary_key=True, index=True) ... quantity = Column(String) # 1 - client, 2 - furnizor price_per_unit = Column(String) company_id = Column(Integer, ForeignKey('Company.id')) company = relationship('Company', back_populates='products', lazy='select') product_id = Column(Integer, ForeignKey('Product.id')) product = relationship('Product', back_populates='companies', lazy='select')This is definitely not the best solution, if I come up with something else or come across something that might work I'll edit it.