page 199 of the SQLAlchemy oreilly book talks about association proxy ;)
On Feb 25, 2009, at 6:12 PM, Stephen Telford wrote:
> Okay, that sounds like a plan but., not to sound too much like a
> broken record, does anyone have an -actual- example ? looking at
> pages with a lot of API's is not really going to help me too much :(
>
> This maybe slightly off-topic and it's really NOT meant as flamebait
> but.. I remember a while ago playing around with DBIx (the perl ORM)
> and one of the things that -really- made it easy to get to grips
> with as the DBIx::Cookbook. It maybe a good idea to fling something
> similiar into the sqlalchemy documentation...
>
> if I had more experience I would write it but.. yes. It definitely
> is the quickest ORM I have seen/used, but, all the speed is for
> naught if you hit the 20% wall.
>
> Regards
> Stef
>
> On Wed, Feb 25, 2009 at 4:21 PM, Michael Bayer <mike...@zzzcomputing.com
> > wrote:
> check out the association proxy extension if you're looking to have
> "Bar" be "hidden" as an association object. it will ultimately use
> Foo/Bar for querying but attribute access would be proxied through
> the names you confgure.
>
>
> On Feb 25, 2009, at 4:11 PM, Stephen Telford wrote:
>
>> Hello Az,
>> Yes, Bar is the association table of Foo to Foo. In essence,
>> this is a self join through a join table.. I have tried and hit my
>> head on this for (quite literally) hours. In the end, and for the
>> record, I ended up creating a method on the model itself such as ;
>>
>> def children(self):
>> childFoo=Foo.__table__.alias()
>> return
>> object_session(self).query(Foo).filter(and_(childFoo.c.deleted ==
>> 0, childFoo.id <> self.id, self.id == Bar.parent_id))
>>
>> Not the prettiest way, nor what I would expect, but in lieu of
>> an actual example, and to help anyone who ends up treading the same
>> path as me, I hope this helps.
>>
>> Regards
>> Stef
>>
>> On Wed, Feb 25, 2009 at 4:29 AM, <a...@svilendobrev.com> wrote:
>>
>> u mean, the Bar is an association table of Foo to Foo?
>> u have to use secondary_table and/or secondary_join in the relation
>> setup. And probably specify remote_side or it may not know which Foo
>> is what.
>>
>> On Wednesday 25 February 2009 03:39:20 Stef wrote:
>> > Hello Everyone,
>> > First of all, kudos on SQLAlchemy.. the speed is pretty amazing
>> > - I am coming from the SQLObject world and there is a definite
>> > difference. Excellent work. I am also getting to grips with it
>> > pretty quickly, using object_session and all that good stuff. This
>> > said, I have hit that 20% problem, and am hoping someone can shine
>> > a light on it.
>> >
>> > I have a table, lets call it Foo and another table Bar. Foo
>> > should be able to get a list of it's parents via Bar or it's
>> > children via Bar. I am also using the declarative_base system
>> > rather than table/ mapper defined seperately.
>> >
>> > class Foo(Base):
>> > id = Column(Integer, primary_key=True)
>> >
>> > class Bar(Base):
>> > parent_id = Column(Integer, default=0)
>> > child_id = Column(Integer, default=0)
>> >
>> > So, I thought something like ; children = relation(Foo,
>> > backref=backref('parents'), primaryjoin=and_(Foo.id==Bar.parent_id)
>> >
>> > But that's where I hit the 'wall' as it were, is there a way to
>> > setup a synonym for Foo in the primaryjoin clause ? Am I missing
>> > something stupid ? (I am okay with that ;)
>> >
>> > Regards
>> > Stef
>> >
>>
>>
>>
>>
>>
>>
>
>
>
>
>
> >
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