Hi Michael,
So how can I prevent this as I can't access the lazyload attributes in my
manager class once I get the result set from DAO as i get no parent
session/contextual session exists exception.
should I maintain a reference to the session object in the DAO class so
that it is not garbage collected ?
thx.
- A
On 4/12/07, Michael Bayer <[EMAIL PROTECTED]> wrote:
>
>
> On Apr 11, 2007, at 11:45 AM, Arun Kumar PG wrote:
>
> Hi Guys,
>
> I am having two layers in my application: Manager and DAO.
>
> DAO deals with ORM and manager simply calls method on DAO.
>
> This is what I am doing in manager
>
> manager:
> rs = dao.getResults (params)
> obj = rs[0]
> some logic.....
> obj.name = 'some name'
> dao.Update(obj)
>
>
> The getResults() in DAOis implemented like this:
>
> def getResults(params):
> s = create_session()
> rs = s.query(....)
> return rs
>
> def Update(obj)
> s = create_session()
> s.update(obj)
> s.flush()
>
> As per the sqlalchemy documentation, we should explicitly expunge() the
> object and then use it with different session. The above logic works fine
> even when the object gettting updated actually belongs to the session that
> was created in the getResults() call.
>
> When I do the same on Python interactive interpreter prompt *without
> having the above methods* it throws:
>
> raise exceptions.InvalidRequestError("Object '%s' is already attached to
> session '%s' (this is '%s')" % (repr(obj), old, id(self)))
>
>
> most likely that the session created in getResults() is falling out of
> scope in your application, therefore the entity is no longer "attached" to
> it (the operation thats throwing that error looks at a session_id attached
> to the object, looks in a WeakValueDictionary for that key to get the
> session). variable scope is more sticky in the python interpreter.
>
>
>
>
> >
>
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