[sqlalchemy] Re: Migrating objects across sessions

2009-01-17 Thread Darren Govoni
After some further experimenting with this, it seems I cannot take a mapped object I retrieved from one session and save it in another. Using expunge then adding the object to a second session on a different database does not work. I thought maybe it would. This is a really useful thing to do,

[sqlalchemy] Re: Migrating objects across sessions

2009-01-17 Thread az
read various threads about copy/deep-copy. in any case u'll have to do the hierarchy-copying yourself - even if moving one object (alone) from session to session succeeds somehow. On Saturday 17 January 2009 14:47:41 Darren Govoni wrote: After some further experimenting with this, it seems I

[sqlalchemy] Re: Migrating objects across sessions

2009-01-17 Thread Darren Govoni
Yes, i'd like to do that, but because of the code injection seems to carry state from the old session, the new session has trouble with even the copy. On Sat, 2009-01-17 at 15:23 +0200, a...@svilendobrev.com wrote: read various threads about copy/deep-copy. in any case u'll have to do the

[sqlalchemy] Re: Migrating objects across sessions

2009-01-17 Thread Darren Govoni
I tried using session.merge(deepcopy) on my copy.deepcopy of a mapped object(s) and when I commit the session I get RuntimeError: maximum recursion depth exceeded strange. On Sat, 2009-01-17 at 15:23 +0200, a...@svilendobrev.com wrote: read various threads about copy/deep-copy. in any case

[sqlalchemy] Re: Migrating objects across sessions

2009-01-17 Thread az
Yes, i'd like to do that, but because of the code injection seems to carry state from the old session, the new session has trouble with even the copy. then, separate the issues: a) make a working deep copy within same session (this is not at all trivial, except for very simple schemas) b)

[sqlalchemy] Re: Migrating objects across sessions

2009-01-17 Thread Michael Bayer
On Jan 17, 2009, at 1:46 PM, Darren Govoni wrote: Hi, Thanks for the suggestions. In my system, it is a federation of databases using SQLA as the object layer. There are message queues that move detched data around as needed. My goal is to keep the application as OO as possible with