如何根据下拉框选择更改 Flask-SQLAlchemy 中的 order_by 子句？

Question

我想让我网站上的用户能够更改从我的数据库中查询获得的结果的顺序（例如按字母升序、按字母降序或通过其他参数）。

这是我要执行 order_by 的查询：

def get_curators_and_total_followers():
    total_playlist_followers =  db.session.query(SpotifyPlaylist.curator_id.label('user_id'), db.func.sum(SpotifyPlaylist.playlist_follower_count).label("total_followers"))\
        .outerjoin(User, SpotifyPlaylist.curator_id==User.id)\
        .group_by(User.id)\
        .subquery()
    curators = db.session.query(User, total_playlist_followers.c.total_followers)\
        .outerjoin(total_playlist_followers, User.id==total_playlist_followers.c.user_id)\
        .join(SpotifyPlaylist, SpotifyPlaylist.curator_id==User.id)\
        .order_by("This is where I want to change the fields")   
    return curators

如何设置默认值以便页面加载，然后根据带有几个不同 order_by 选项的下拉框为用户提供以不同方式显示结果的选项？

Answer 1

def get_curators_and_total_followers():
    total_playlist_followers =  db.session.query(SpotifyPlaylist.curator_id.label('user_id'), db.func.sum(SpotifyPlaylist.playlist_follower_count).label("total_followers"))\
        .outerjoin(User, SpotifyPlaylist.curator_id==User.id)\
        .group_by(User.id)\
        .subquery()
    curators = db.session.query(User, total_playlist_followers.c.total_followers)\
        .outerjoin(total_playlist_followers, User.id==total_playlist_followers.c.user_id)\
        .join(SpotifyPlaylist, SpotifyPlaylist.curator_id==User.id)\
    
    order_by = form.get('orderBy')
    if order_by is None:
        curators.order_by("your default value")
    else:
        curators.order_by(order_by)
        
    return curators