Question

我正在尝试根据用户给出的评分来计算游戏的平均评分。我的models.py重要部分看起来像这样

class Review(db.Model):
  id = db.Column(db.Integer, primary_key=True)
  rating = db.Column(db.Numeric(precision=2, scale=1), index=True)
  body = db.Column(db.String(140))
  user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
  game_id = db.Column(db.Integer, db.ForeignKey('game.id'))

class Game(db.Model):
  id = db.Column(db.Integer, primary_key=True)
  title = db.Column(db.String(255), index=True, unique=True)
  reviews = db.relationship('Review', backref='game', lazy='dynamic')

  def avg_rating(self):
    ratings = Review.query.with_entities(Review.rating).filter_by(game_id=self.id).all()
    return sum(ratings) / len(ratings)

和routes.py

中

games = Game.query.order_by(Game.avg_rating.desc()).all()

但是我得到这个错误

'function' object has no attribute 'desc'

如何获得按平均评分排序的游戏列表？

编辑

我将我的models.py avg_rating函数更改为混合属性

@hybrid_property
def avg_rating(self):
  total_rating = 0
  reviews = Review.query.filter_by(game_id=self.id).all()
  for review in reviews:
    total_rating += review.rating

  return total_rating / len(reviews)

现在我收到此错误

AttributeError: 'decimal.Decimal' object has no attribute 'desc'

通过降低flask-sqlalchemy

编辑

0 个答案: