Hi Michael,
As expected the trunk works perfectly. I am also looking into the comparator example you pointed to as this looks like it will help with a couple of other implementation details as well. Thanks again, Martin On Feb 20, 10:25 pm, Martin Pengelly-Phillips <[EMAIL PROTECTED]> wrote: > Thank you Michael - it's always good to get some validation when > pushing your own knowledge of a system. > I'll check out the trunk tomorrow, give it a whirl and report any > findings then. > > Thanks again for the quick response, > > Martin > > On Feb 20, 6:31 pm, Michael Bayer <[EMAIL PROTECTED]> wrote: > > > On Feb 20, 2008, at 1:01 PM, Martin Pengelly-Phillips wrote: > > > > I have attempted to solve this by using the concept of > > > 'forwardAssociations' with a backref of 'backwardAssociations' and > > > then a custom property 'associations' that retrieves and sets the real > > > attributes accordingly (let me know if you would like to see this code > > > as well). However, even with this set up I find it hard to figure out > > > how to then perform a query such as: > > > > # Get all entities that are in some way associated with entity 2 > > > (without using entity2.associations property) > > > session.query(Entity).filter(or_( > > > Entity.forwardAssociations.any(Entity.id==2), > > > Entity.backwardAssociations.any(Entity.id==2) > > > )).all() > > > > The query this generates though uses the same id for both sides of the > > > association table which cannot therefore result in a match: > > > entities.id = "entitiesEntities".entity1_id AND > > > "entitiesEntities".entity2_id = entities.id AND entities.id = ? > > > well i think everything you're doing is on the right track. The any() > > operator and its friends have just been repaired in the latest trunk > > to recognize a self-referential relation and apply the appropriate > > aliasing to half of the join condition. I haven't tested it with a > > many-to-many self referential yet but I think it should work. give it > > a try and let me know what you get; I can add some m2m tests for it > > and ensure that its working if its not already. > > > we also are working on getting better support for user-defined custom > > properties going such that they can be seamlessly used within Queries, > > so that you could also construct your query using your "associations" > > property, if you can define how comparison operations should be done. > > There is a way to do this right now using a slight bit of "non-public" > > API, where you can see an example of such > > inhttp://www.sqlalchemy.org/trac/browser/sqlalchemy/trunk/examples/vert... > > ; the "comparable_property" allows the injection of a Comparator > > object from where you can define things like __eq__(), any(), etc. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
