Michael, Thanks for your reply.
The use case is configuration management. We have complex (SQLAlchemy) objects with many relationships which we wish to up-version, i.e. we want an exact persistent copy (attribute values and relationships) of the original object, but with a different identity, which we will then modify. The original object and all its relationships should remain unchanged (other than a relationship to its successor version). We would want the copied object and all its relationships saved to the database before making changes to it. Regards, Tim 2008/9/9 Michael Bayer <[EMAIL PROTECTED]> > > copy.copy() is going to have issues since you'd be copying the > _sa_state of the instance as well. "copying" an object that is SQLA > mapped implies a particular use case in mind, depending on this use > case is what would determine how you get your "copy". > > Would you like to get a "copy" that is simply the same object with the > same identity, just as present in another session (in which case use > merge()) ? > > Or would you like to get a "copy" that is a transient (no database > identity) copy of that object, with all attributes except primary key > attributes copied over ? ( in which case you'd use a copy constructor > which possibly uses mapping metadata to traverse ) ? > > > On Sep 9, 2008, at 2:16 PM, [EMAIL PROTECTED] wrote: > > > > > u can try: > > from copy import copy > > dest = copy(src) > > it has pickle semantics, YMMV - i have not tried on SA objects. > > i use my own, see my post in this thread with some (complex) code: > > > http://groups.google.com/group/sqlalchemy/tree/browse_frm/thread/2369b78e0f8e21cb/4dd4979ca8501fba > > > > On Tuesday 09 September 2008 18:59:09 picoplex wrote: > >> Is there a quick way to copy an object (including all its > >> relationships as well as its attributes)? > >> > >> Regards, > >> > >> Tim > >> > > > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
