agronholm

class Author(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    forenames = db.Column(db.String(120), index=True)
    lastname = db.Column(db.String(120), index=True)

    associations = db.relationship('ArticleAuthor', backref='author')
    articles = association_proxy('associations', 'article')


#intermediate table used for ordering authors within articles

agronholm

start_date = arrow.utcnow().replace(months=-2).datetime
end_date = arrow.utcnow().datetime

gen_stmt = db.session.query(func.generate_series(start_date, end_date, timedelta(1)).label('day')).subquery()
donation_day = func.date_trunc(time_unit, Donation.created).label('day')
donation_stmt db.session.query(donation_day, func.sum(Donation.amount).label('amount_raised')).\
    filter(created.between(start_date, end_date)).group_by(donation_day).subquery()
query = db.session.query(gen_stmt, coalesce(donation_stmt.c.amount_raised, 0)).outerjoin(donation_stmt, gen_stmt.c.day == donation_stmt.c.day)