Many to many relationship in Flask with SQLAlchemy

Question

I want to create a family tree where the relationships are only godfather and godson. Is this the right way to declare the personn class ?

from sqlalchemy import Column, ForeignKey
from sqlalchemy.ext.declarative import declarative_base
from genealogie.extensions import db
Base = declarative_base()
relationship = db.Table('relationship', Base.metadata,
 Column('godfather', db.Integer, ForeignKey('personn.id'), primary_key=True),
 Column('godson', db.Integer, ForeignKey('personn.id'), primary_key=True))
class Personn(db.Model):
 __tablename__ = 'personn'
 id = Column('id', db.Integer, primary_key=True)
 first_name = Column('first_name', db.String(255), nullable=False)
 last_name = Column('last_name', db.String(255), nullable=False)
 birthdate = Column('birthdate', db.DateTime, nullable=True)
 promo = Column('promo', db.Integer, nullable=False)
 description = Column('description', db.Text, nullable=True)
 godfather = db.relationship('Personn',
 secondary=relationship,
 primaryjoin=relationship.c.godfather==id,
 secondaryjoin=relationship.c.godson==id,
 backref="godson")

• Vogel612: soo ... how does your database cover the possibility of multiple godparents? Or of multiple godchildren?
• louisld: With the relationship table

Answer 1

Is this the right way to declare the personn class ?

Yes. It looks good to me.

Ship it!