Thank you Michael,
I will try it... next year... ^^
good 2011 again!
neurino
On Dec 30, 5:45 pm, Michael Bayer <mike...@zzzcomputing.com> wrote:
> this is again my error messages not telling the whole story, ill see if i can
> get the term "foreign_keys" back in there:
>
> mapper(Sensor, sensors,
> properties={
> 'data': relationship(Data, backref='sensor',
> foreign_keys=[data.c.id_meas],
> primaryjoin=and_(sensors.c.id_meas==data.c.id_meas,
> data.c.id_acq==acquisitions.c.id,
> acquisitions.c.id_cu==sensors.c.id_cu),
> cascade='all, delete-orphan', single_parent=True)
> })
>
> or
>
> mapper(Sensor, sensors,
> properties={
> 'data': relationship(Data, backref='sensor',
> foreign_keys=[sensors.id_meas],
> primaryjoin=and_(sensors.c.id_meas==data.c.id_meas,
> data.c.id_acq==acquisitions.c.id,
> acquisitions.c.id_cu==sensors.c.id_cu),
> cascade='all, delete-orphan', single_parent=True)
> })
>
> depending on if this is one-to-many or many-to-one. A relationship like
> this is really better off as a viewonly=True since populating it is not going
> to add rows to the "acquisitions" table.
>
> On Dec 30, 2010, at 10:15 AM, neurino wrote:
>
>
>
>
>
>
>
> > data = Table('data', metadata,
> > Column('id', Integer, primary_key=True),
> > Column('id_acq', Integer, ForeignKey('acquisitions.id'),
> > nullable=False),
> > Column('id_meas', Integer, nullable=False),
> > Column('value', Float, nullable=True),
> > )
>
> > acquisitions = Table('acquisitions', metadata,
> > Column('id', Integer, primary_key=True),
> > Column('id_cu', Integer, ForeignKey('ctrl_units.id'),
> > nullable=False),
> > Column('datetime', DateTime, nullable=False),
> > )
>
> > sensors = Table('sensors', metadata,
> > Column('id_cu', Integer, ForeignKey('ctrl_units.id'),
> > primary_key=True,
> > autoincrement=False),
> > Column('id_meas', Integer, primary_key=True, autoincrement=False),
> > Column('name', Unicode(20), nullable=False),
> > Column('desc', Unicode(40), nullable=False),
> > )
>
> > ctrl_units = Table('ctrl_units', metadata,
> > Column('id', Integer, primary_key=True, autoincrement=False),
> > Column('desc', Unicode(40), nullable=False)
> > )
>
> > and this mapping:
>
> > ...
> > orm.mapper(Sensor, sensors,
> > properties={
> > 'data': orm.relationship(Data, backref='sensor',
> > primaryjoin=and_(sensors.c.id_meas==data.c.id_meas,
> > data.c.id_acq==acquisitions.c.id,
> > acquisitions.c.id_cu==sensors.c.id_cu),
> > cascade='all, delete-orphan', single_parent=True)
> > })
> > ...
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