Python 在查询中使用“分组依据”时，从每个组中选择一个元素

我想知道在查询GROUPBY时如何从类中提取任意元素。例如：

class Post(Base):
    id = Column(Integer, primary_key=True)
    created = Column(DateTime)
    comments = Column(Integer)
    creator = Column(Integer, ForeignKey('user.id'))
    anonymous = Column(Boolean)

class User(Base):
    id = Column(Integer, primary_key=True)

如何创建输出以下内容的查询：

creator | total number of comments made on the creator's post | the time of the creator's last post

creator | total number of comments made on the creator's post | if any of the posts are anonymous

基本问题是：

session = DBSession()
commsum = session.query(Post.creator, func.sum(Post.comments).label('totalcomments')).\
    group_by(Post.creator).subquery()
return session.query(User, commsum.c.totalcomments).\
    join(commsum, commsum.c.creator == User.id).all()

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如果我想返回1每个组中所有行的最新日期_byPost.creator，或者如果其中任何一行的anonymous==True，该怎么办

SELECT Post.creator, 
       sum(Post.comments) total_comments
       max(Post.Created) latest_post
       max(Post.anonymous) any_anonymous
FROM Post
GROUP BY Post.creator

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你现在有什么？你试过什么？请使用此信息更新您的问题。尚未尝试任何操作，正在忙于其他任务。我只是在寻找解决方案，但找不到任何解决方案。