On Aug 12, 2010, at 5:09 PM, Michael Bayer wrote:
>
> On Aug 12, 2010, at 4:58 PM, Alvaro Reinoso wrote:
>
>> I'm still working on the solution. I've found out some stuff in
>> internet. I guess I'm close to, but I haven't got it yet. I'm using
>> this for the relation:
>>
>> mediaGroups = relationship("MediaGroup",
>> secondary=media_group_groups, order_by="MediaGroup.title",
>> backref='media_groups', foreign_keys =
>> ["media_group_groups.groupA_id", "media_group_groups.groupB_id"],
>> primaryjoin = "MediaGroup.id ==
>> media_group_groups.groupA_id",
>> secondaryjoin = "MediaGroup.id == media_group_groups.groupB_id")
>>
>> I'm playing with the parameters, but I usually get this error:
>>
>> "ArgumentError: Could not determine relationship direction for
>> primaryjoin condition 'users.id = :id_1', on relationship
>> User.mediaGroups. Specify the 'foreign_keys' argument to indicate
>> which columns on the relationship are foreign."
>
> "media_group_groups" is not available when "primaryjoin" is evaluated as a
> string, nor within "foreign_keys" which is not necessary here since your
> meta_group_groups already has ForeignKey objects on it, so use a non-string
> format for primaryjoin. i will add additional examples to the declarative
> docs.
scratch part of that, tablenames are available in the string eval as long as
they're from the same MetaData:
mediaGroup = relationship("MediaGroup",
secondary=media_group_groups, order_by="MediaGroup.title",
backref="media_groups",
primaryjoin="MediaGroup.id==media_group_groups.c.groupA_id",
secondaryjoin="MediaGroup.id==media_group_groups.c.groupB_id"
also the error for the exampe you have above should be "'Table' object has no
attribute 'groupA_id'".
>
>
>>
>> Thank you!
>>
>> On Aug 12, 1:08 pm, Alvaro Reinoso <alvrein...@gmail.com> wrote:
>>> Hello,
>>>
>>> I'm trying to link one table to itself. I have media groups which can
>>> contain more media group. I created a relation many to many:
>>>
>>> media_group_groups = Table(
>>> "media_group_groups",
>>> metadata,
>>> Column("groupA_id", Integer,
>>> ForeignKey("media_groups.id")),
>>> Column("groupB_id", Integer,
>>> ForeignKey("media_groups.id"))
>>> )
>>>
>>> class MediaGroup(rdb.Model):
>>> """Represents MediaGroup class. Conteins channels and other media
>>> groups"""
>>> rdb.metadata(metadata)
>>> rdb.tablename("media_groups")
>>>
>>> id = Column("id", Integer, primary_key=True)
>>> title = Column("title", String(100))
>>> parents = Column("parents", String(512))
>>>
>>> channels = relationship(Channel, secondary=media_group_channels,
>>> order_by=Channel.titleView, backref="media_groups")
>>> mediaGroup = relationship("MediaGroup",
>>> secondary=media_group_groups, order_by="MediaGroup.title",
>>> backref="media_groups")
>>>
>>> I got this error:
>>>
>>> "ArgumentError: Could not determine join condition between parent/
>>> child tables on relationship MediaGroup.mediaGroup. Specify a
>>> 'primaryjoin' expression. If this is a many-to-many relationship,
>>> 'secondaryjoin' is needed as well."
>>>
>>> When I create the tables I don't get any error, it's just when I add
>>> any element to it.
>>> Any idea???
>>>
>>> Thanks in advance!
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "sqlalchemy" group.
>> To post to this group, send email to sqlalch...@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.
>>
>
> --
> You received this message because you are subscribed to the Google Groups
> "sqlalchemy" group.
> To post to this group, send email to sqlalch...@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.
>
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To post to this group, send email to sqlalch...@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.
