Worked like magic!! Thanks!
BTW, why wasn't SQLA able to determine this automatically like it
usually does?
On Jun 5, 11:30 am, Michael Bayer <[EMAIL PROTECTED]> wrote:
> On Jun 5, 2008, at 11:18 AM, Tomer wrote:
>
>
>
>
>
> > Hi,
>
> > I have two tables: Image and PersistentImage, where the latter
> > inherits the former. In addition, PersistentImage has a foreign key to
> > itself (ie, all PersistentImage objects form a hierarchy among
> > themselves). I haven't been able to get this to work - first it
> > complained about wanting a primaryjoin, then it seemed to get confused
> > between the parent/children relation among PersistentImage objects and
> > the inheritance between PersistentImage and Image. Here are my
> > mappers:
>
> > mapper(
> > Image,
> > imageTable,
> > polymorphic_on=imageTable.c.type,
> > polymorphic_identity='Image'
> > )
>
> > mapper(
> > PersistentImage,
> > persistentImageTable,
> > inherits=Image,
> > polymorphic_identity='PersistentImage',
> > properties={
> > 'children': relation(PersistentImage, backref='parent')
> > })
>
> > And here are the actual table definitions:
>
> > imageTable = Table('Images', metadata,
> > Column('id', Integer, primary_key=True),
> > Column('name', String(256), nullable=False),
> > Column('type', String(30), nullable=False)
> > )
>
> > persistentImageTable = Table('PersistentImages', metadata,
> > Column('id', Integer, ForeignKey('Images.id'), primary_key=True),
> > Column('parentId', Integer, ForeignKey('PersistentImages.id')),
> > Column('userId', Integer, ForeignKey('Users.id'), nullable=False)
> > )
>
> here it is:
>
> mapper(PersistentImage, persistentImageTable, inherits=Image,
> inherit_condition=persistentImageTable.c.id==imageTable.c.id,
> polymorphic_identity='PersistentImage',
> properties={
> 'children':relation(PersistentImage,
> primaryjoin=persistentImageTable.c.parentId==persistentImageTable.c.id,
> backref=backref('parent',
> primaryjoin
> =persistentImageTable.c.parentId==persistentImageTable.c.id,
> remote_side=[persistentImageTable.c.id])
> )
> })
>
> SQLA would probably slightly happier if you had the "parentId" foreign
> key referencing Images.id instead of PersistentImages.id but this
> should not be required.
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