models.py

from sqlalchemy import Column, Integer, String, ForeignKey
from sqlalchemy.orm import relationship, backref, declarative_base

Base = declarative_base()

class Company(Base):
    __tablename__ = 'companies'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    founding_year = Column(Integer)
    freebies = relationship('Freebie', back_populates='company')
    devs = relationship('Dev', secondary='freebies', back_populates='companies', viewonly=True)

    def give_freebie(self, dev, item_name, value):
        freebie = Freebie(item_name=item_name, value=value, company=self, dev=dev)
        return freebie

    @classmethod
    def oldest_company(cls, session):
        return session.query(cls).order_by(cls.founding_year).first()

class Dev(Base):
    __tablename__ = 'devs'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    freebies = relationship('Freebie', back_populates='dev')
    companies = relationship('Company', secondary='freebies', back_populates='devs', viewonly=True)

    def received_one(self, item_name):
        return any(f.item_name == item_name for f in self.freebies)

    def give_away(self, dev, freebie):
        if freebie in self.freebies:
            freebie.dev = dev

class Freebie(Base):
    __tablename__ = 'freebies'
    id = Column(Integer, primary_key=True)
    item_name = Column(String)
    value = Column(Integer)
    company_id = Column(Integer, ForeignKey('companies.id'))
    dev_id = Column(Integer, ForeignKey('devs.id'))
    company = relationship('Company', back_populates='freebies')
    dev = relationship('Dev', back_populates='freebies')

    def print_details(self):
        return f"{self.dev.name} owns a {self.item_name} from {self.company.name}"