I have a model where I have articles and images, with a many-to-many
relation between them. Since the order of images for an article is
important this relation should be ordered from the article site. My
naieve implementation looks like this:
article_images = Table('article_image', BaseObject.metadata,
Column('article_id', Integer(),
ForeignKey('article.id',
onupdate='CASCADE', ondelete='CASCADE'),
primary_key=True),
Column('image_id', Integer(),
ForeignKey('image.id',
onupdate='CASCADE', ondelete='CASCADE'),
primary_key=True),
Column('position', Integer()))
class Image(BaseObject):
__tablename__ = 'image'
id = Column(Integer(),
Sequence('image_id_seq', optional=True),
primary_key=True, autoincrement=True)
path = Column(String(128), nullable=False, unique=True)
class Article(BaseObject):
__tablename__ = 'article'
id = Column(Integer(),
Sequence('article_id_seq', optional=True),
primary_key=True, autoincrement=True)
#: An ordered list of images for this article. The first image
#: is considered to be the *key* image.
images = relationship(Image,
order_by=[article_images.c.position],
secondary=article_images,
collection_class=ordering_list('position'))
Unfortunately this breaks since OrderingList assumes that the position
attribute is set on Image instead of the article_images table. From what
I can see this is not easily fixed since OrderingList only gets the list
of Image instances and doesn't have access to the related article_images
row. Is there another way to accomplish this?
Wichert.
--
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
sqlalchemy+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/sqlalchemy?hl=en.
