Hi Connor, On 13 oct, 18:23, Conor <conor.edward.da...@gmail.com> wrote: > On 10/13/2010 10:55 AM, Christophe de Vienne wrote: > > > > > Hi all, > > > I am running into an issue with MapperExtension.[before|after]_update. > > > [...] > > AFAIK SQLAlchemy does not support the following in MapperExtensions: > > * lazy-loading related objects (maybe?)
It looks like this. Because if I make sure the related objects are loaded before flushing the problem. > * changing the "flush plan", which I believe means changing which > objects are considered new, dirty, or deleted Which is why I do a double flush. > Your code is possibly trying to do both. Yep, but the disturbing thing is that I could not reproduce the issue in a small example, hence my question. > You need to instead create a > SessionExtension and override before_flush, which allows you to modify > the session however you want, e.g. (untested): > > class MySessionExtension(object): > def before_flush(self, session, flush_context, instances): > for obj in session.dirty: > if isinstance(obj, Parent): > for child in obj.children: > child.name = 'another name' This is a very interesting idea, which beside solving my issue (hopefully) would also avoid a double-flush. I guess I should also have a look to AttributeExtension which could be a solution in my case. Thanks, Christophe -- 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.
