models.py

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

# naming conventions for constraints

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

Base = declarative_base(metadata=metadata)

class Company(Base):
    __tablename__ = 'companies'

    id = Column(Integer(), primary_key=True)
    name = Column(String())
    founding_year = Column(Integer())
    # relationships
    freebies=relationship("Freebie", back_populates="company")

    devs=relationship(
        "Dev",
        secondary="freebies",
        back_populates="companies",
        viewonly=True
    )

    def __repr__(self):
        return f'<Company {self.name}>'

class Dev(Base):
    __tablename__ = 'devs'

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

    # relationships
    freebies=relationship("Freebie", back_populates="dev")

    companies=relationship(
        "Company",
        secondary="freebies",
        back_populates="devs",
        viewonly=True
    )

    def __repr__(self):
        return f'<Dev {self.name}>'
    
    
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 __repr__(self):
        return f'<Freebie {self.item_name} ({self.value})>'
    

    # Here we added Freebie class because the project is called freebie tracker
    # Establish relationship between companies, devs and freebies