What's strange is that I can't recreate the problem on more simple stage. Every time I refresh() on the parent object, the list objects remain the same. In other words, *sometimes* it behaves as I hope it to (by apparently refreshing the list's objects) and *sometimes* if throws them out and creates new ones. The mystery to me is what determines when it will create new instances vs. refreshing the existing ones?
On Mar 4, 3:24 pm, "Michael Bayer" <mike...@zzzcomputing.com> wrote: > Kent wrote: > > If I use session.refresh(obj) to re-load an obj that has a one-to-many > > relational property, the objects in the list are *replaced* instead of > > *refreshed* if they already exist. > > > Suppose department has a list of employees: > > > suppose dept.employees = [ emp1, emp2 ] > > > session.refresh(dept) > > > the dept."employees" list's elements are replaced with new objects > > instead of reusing those that existed and refreshing them. > > > Is it possible to have those same objects re-used and simply refreshed > > instead of replaced? > > you can only turn off "refresh-expire" cascade, which will prohibit the > operation from traveling into the child objects. the collection is still > refreshed for obvious reasons, its one of the attributes on your mapped > object. > > To achieve your specified behavior, use session.refresh() given as its > second argument the set of attribute names which are safe to be reloaded > completely (in this case the scalars). Then for each uselist attribute, > iterate the collection of each and call the desired version of > session.refresh() for those. > > This is an easy refresh() function to create in a generalized way by > inspecting the class-level attributes of the incoming object. > > > > > -- > > You received this message because you are subscribed to the Google Groups > > "sqlalchemy" group. > > To post to this group, send email to sqlalch...@googlegroups.com. > > To unsubscribe from this group, send email to > > sqlalchemy+unsubscr...@googlegroups.com. > > For more options, visit this group at > >http://groups.google.com/group/sqlalchemy?hl=en. > > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalch...@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
