models.py

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

convention = {
    "fk": "fk_%(table_name)s_%(column_0_name)s_%(referred_table_name)s",
}
metadata = MetaData(naming_convention=convention)

Base = declarative_base()

class Company(Base):
    __tablename__ = 'companies'

    id = Column(Integer(), primary_key=True)
    name = Column(String())
    founding_year = Column(Integer())

    def __repr__(self):
        return f'<Company {self.name}>'
    
    @property
    def devs(self):
        return list({freebie.dev for freebie in self.freebies})

class Dev(Base):
    __tablename__ = 'devs'

    id = Column(Integer(), primary_key=True)
    name= Column(String())

    def __repr__(self):
        return f'<Dev {self.name}>'
    
    @property
    def companies(self):
        return list({freebie.company for freebie in self.freebies})
    
class Freebie(Base):
    __tablename__ = "freebies"

    id = Column(Integer(), primary_key = True)
    item_name = Column(String())
    value = Column(Integer())

    dev_id = Column(Integer, ForeignKey('devs.id'))
    company_id = Column(Integer, ForeignKey('companies.id'))

    dev = relationship("Dev", backref="freebies")
    company = relationship("Company", backref = "freebies")

    def __repr__(self):
        return f"<Freebie {self.item_name} - ${self.value}>"
    
    def print_details(self):
        return f"{self.dev.name} has a {self.item_name} from {self.company.name}"