Many to Many relationship calling on Flask SQL Alchemy

Question

I have the following badge (achievement) system database structure:

class Base(db.Model):

__abstract__ = True

id = db.Column(db.Integer, primary_key=True)
date_created = db.Column(db.DateTime, default=db.func.current_timestamp())
date_modified = db.Column(db.DateTime, default=db.func.current_timestamp(),
                          onupdate=db.func.current_timestamp())

class User(UserMixin, Base):

__tablename__ = 'users'

username = db.Column(db.String(20), nullable=False, unique=True)
email = db.Column(db.String(50), nullable=False, unique=True)
password = db.Column(db.String(200), nullable=False)
name = db.Column(db.String(30), nullable=False)
badges = db.relationship('UserBadge', backref='ubadge',
                            lazy='dynamic')

class Badge(Base):

__tablename__ = 'badges'

name = db.Column(db.String(35), unique=True)
description = db.Column(db.String(300))
imgfile = db.Column(db.String(80))
badges = db.relationship('UserBadge', backref='badge',
                            lazy='dynamic')

def __repr__(self):
    return '<Achievement: {} - {}>'.format(self.name, self.description)

class UserBadge(Base):

__tablename__ = 'userbadges'

user_id = db.Column(db.Integer(), db.ForeignKey('users.id'))
badge_id = db.Column(db.Integer(), db.ForeignKey('badges.id'))

def __repr__(self):
    return '<Achievement: {} - {}>'.format(self.user_id, self.badge_id)

So i can return all the badges by a specific user, using:

ubadges = UserBadge.query.filter_by(user_id=user.id).all()

It returns:

 [<Achievement: 1 - 1>]

But instead of 1 (user_id) and 1 (badge_id) i want to show the users.name and badges.name. How can i access those attributes?

Answer 1

In your UserBadge class, just use:

def __repr__(self):
    return '<Achievement: {} - {}>'.format(self.ubadge.name, self.badge.name)

It has both properties because you set them up using backref in the other classes.

PS: You might need to change the User backref to user, and then use self.user.name int he function above