Tested with trunk. Works, thanks.
On Jan 29, 6:42 am, Michael Bayer <mike...@zzzcomputing.com> wrote:
> OK, well that was painful but we are stronger for the effort, thanks
> for bringing up the issue. r5740 of trunk will allow your original
> mapper(A.join(B))->mapper(B) to configure properly.
>
> On Jan 28, 2009, at 11:28 PM, Michael Bayer wrote:
>
>
>
> > a join is of the form:
>
> > table1.join(table2, onclause)
>
> > such as
>
> > subscriber_table.join(address_table,
> > and_(address_table.c.subscriber_id==subscriber.c.id,
> > address_table.c.type=='MAIN'))
>
> > but unfortunately current relation() code does not support a join of
> > X/
> > Y to Y, unless the join of X/Y is assembled via joined table
> > inheritance. As a workaround, you can wrap your join() in an
> > aliased select(). A fix may be available in the next 10 minutes or
> > maybe not.
>
> > You also could forego the complexity of mapping to a join and just
> > modify your Subscriber class to break up the "addresses" collection
> > amongst a proxy of the "MAIN" element and a list of the remaining
> > elements. an attribute_mapped_collection could help to accomplish
> > this nicely.
>
> > On Jan 28, 2009, at 7:22 PM, GHZ wrote:
>
> >> I have a subscriber and address table.
>
> >> a subscriber will have one and only one 'MAIN' address.
> >> I want the subscriber and MAIN address to be represented by one class
> >> 'Subscriber'. However, I want that class to have a collection
> >> 'addresses' which contains other addresses (e.g. old addresses) - (it
> >> can include the 'MAIN' address too .. or not.. I don't care)
>
> >> subscriber_table = Table('subscriber', metadata,
> >> Column('id', primary_key=True),
> >> autoload=True)
>
> >> address_table = Table('address',
> >> metadata,
> >> Column('subscriber_id', ForeignKey
> >> ('subscriber.id'), primary_key=True),
> >> Column('address_type', primary_key=True),
> >> autoload=True)
>
> >> subscriber_with_default_address = sql.join( subscriber_table.c.id
> >> == address_table.c.subscriber_id).??? <- something to say
> >> address_table.type is 'MAIN'
>
> >> mapper(Address, address_table)
>
> >> mapper(Subscriber, subscriber_and_address, properties={
> >> 'id':[subscriber_table.c.id, address_table.c.subscriber_id],
> >> 'addresses' : relation(Address, collection_class=Addresses,
> >> backref='customer')
> >> })
>
> >> a) I can't quite figure out how to say (address.type is default)
> >> b) even without this I get:
>
> >> sqlalchemy.exc.ArgumentError: Can't determine relation direction for
> >> relationshi
> >> p 'Subscriber.addresses' - foreign key columns are present in both
> >> the
> >> parent an
> >> d the child's mapped tables. Specify 'foreign_keys' argument.
>
> >> if I do specify foreign_keys parameter to the relation function, then
> >> I still get the same.
>
> >> Thanks
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