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使用Beaker Cache和SQLAlchemy
原标题:Working with Beaker Cache and SQLAlchemy

我正在尝试将烧杯缓存与SQLAlchemy一起使用,但我一直收到错误。

这是我的表格定义。

class Post(Base):
  ....
  ....

  user = relation(User, primaryjoin = User.id == id)
  tags = relation( Tags , backref =  posts )


class Tags(Base):
  ...
  ...

  user = relation(User, primaryjoin = User.id == id)
  post = relation(Post, primaryjoin = Post.id == id)

烧杯缓存可以与除这些类之外的其他SQLAlchemy类一起使用。

当我运行程序时,我收到以下错误;

DetachedInstanceError: Parent instance <Post at 0x101f90b10> is not bound 到a Session; lazy load operation of attribute  user  cannot proceed.

我在StackOverFlow上搜索过,在另一个线程中发现我需要禁用延迟加载,所以我更改了行

user = relation(User, primaryjoin = User.id == id)

user = relation(User, primaryjoin = User.id == id, lazy= dynamic )

but this occurs 到following error in template(post.user.fullname);

AttributeError:  AppenderQuery  object has no attribute  fullname 

我做错了什么?

最佳回答

当您从缓存中获取对象时,应该将它们与会话对象相关联,例如。

obj_from_cache = get_from_cache(key)
session.merge(obj_from_cache)
问题回答

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