Thank you Mike!
So suppose I have an a Manager object *manager* and I wanted to promote
that to Engineer:
# Modify the persisted data of the manager object in the db directly.
session = object_session(manager)
session.execute(manager.__table__.update() \
.where(manager.__table__.c.id == manager.id
) \
.values({'type': 'engineer'}))
# session.flush() ?
# Expunge the object.
session.expunge(manager)
# Subsequent reads would then return Engineer objects…
I suspect that modifying the object directly would not work with expunge().
However, if I wouldn't expunge() and all I do is modify the object then
perhaps that's ok?
# Modify the object's type directly, then manager's class would not be
accurate anymore.
manager.type = "engineer"
Also, if for some reason the session were to rollback() then the above
execute() would not be persisted and manager remain a manager. Correct?
Thanks!
Jens
On Thursday, August 10, 2017 at 5:25:37 PM UTC+2, Mike Bayer wrote:
>
> > Talking about the example in the documentation, do I understand you
> > correctly that changing from Manager to Engineer is as simple as
> updating
> > the type field?
>
> yes. also locally you want to clear out those objects from your
> Session and reload (cleanest would be to expunge() totally).
>
>
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