Hi,
Maybe you should take a look at sqlamp (http://sqlamp.angri.ru/)
Regards,
Laurent
Le 22/09/2009 18:01, Shuaib Osman a écrit :
> Hi guys,
>
> I’m to build an adjacency list in SA and have looked at the
> basic_tree.py example provided, however, I need to order the children.
> Now I don’t really want to use nested sets and I know linked lists can
> be implemented in SA quite easily.
>
> So naturally I tried something like
>
> trees = Table('treenodes', metadata,
> Column('id', Integer, Sequence('treenode_id_seq', optional=True),
> primary_key=True),
> Column('parent_id', Integer, ForeignKey('treenodes.id'),
> nullable=True),
> Column('name', String(50), nullable=False),
> Column('next_id', Integer, ForeignKey('treenodes.id'),
> unique=True, nullable=True)
> )
>
> mapper(TreeNode, trees, properties={
> 'children': relation(TreeNode, cascade="all",
> backref=backref("parent", remote_side=
> [trees.c.id]),
>
> collection_class=attribute_mapped_collection('name'),
> lazy=False, join_depth=3),
> 'next' : relation(TreeNode, uselist=False,
>
> remote_side=trees.c.id,
> backref=backref('previous',
> uselist=False))}
> )
>
> Of course this does not work as it's a many to many relation (and so
> needs another table). I would really prefer if I could get away with
> just using one table though. Is there a way to do it?
>
> Thanks.
>
> >
>
--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---
