oh that should be mapper(TrafficInput, sel, non_primary=True)
On Jul 26, 2013, at 10:41 AM, Michael Bayer <[email protected]> wrote: > you'd need to make a relationship() that explicitly joins out among all four > tables so that the .Time column is available. To accomplish that you'd > probably want to make a non primary mapper to join to, it would look > something like this: > > sel = select([TrafficInput, > Traffic.Time]).select_from(join(TagCaseLink, > TrafficInput).join(TrafficDevice).join(Traffic)).alias() > m = mapper(TrafficInput, sel) > > TagList.trafficInputs = relationship(m, order_by=sel.c.Time) > > It's probably not how I'd go as it's too complicated. I'd either change the > schema to work more naturally (that you need to join across four tables to > get a certain ordering is a bit of a red flag) or possibly just order in > memory, assuming those relationships all tend to get loaded. > > > > > > On Jul 26, 2013, at 3:26 AM, Andrew S <[email protected]> wrote: > >> Given the following classes/tables: >> class TagList(Base): >> TagID = Column(Integer, primary_key=True) >> trafficInputs = relationship('TrafficInput', secondary='TagCaseLink', >> order_by='Traffic.Time') >> >> class TagCaseLink(Base): >> TagID = Column(Integer, ForeignKey('TagList.TagID'), primary_key=True) >> TrafficInputID = Column(Integer, >> ForeignKey('TrafficInput.TrafficInputID')) >> >> class TrafficInput(Base): >> TrafficInputID = Column(Integer, primary_key=True) >> TrafficDeviceID = Column(Integer, >> ForeignKey('TrafficDevice.TrafficDeviceID'), nullable=False) >> ConfigID = Column(Integer, ForeignKey('Config.ConfigID'), nullable=False) >> >> class TrafficDevice(Base): >> TrafficDeviceID = Column(Integer, primary_key=True) >> TrafficID = Column(Integer, ForeignKey('Traffic.TrafficID'), >> nullable=False) >> DeviceID = Column(Integer, ForeignKey('Device.DeviceID'), nullable=False) >> >> class Traffic(Base): >> TrafficID = Column(Integer, primary_key=True) >> TrafficName = Column(String, nullable=False) >> Time = Column(DateTime, nullable=False) >> >> I get the following error: sqlalchemy.exc.ProgrammingError: >> (ProgrammingError) missing FROM-clause entry for table "Traffic" >> >> So TagList contains a list of trafficInputs that I want ordered by >> Traffic.Time. Is there anyway of doing this? >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sqlalchemy" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/sqlalchemy. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> > > > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/groups/opt_out. > > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/groups/opt_out.
