Do you have the "metadata" in Table shared with the metadata used by DeclarativeBase ? Otherwise the name "ticket" won't be located via the ForeignKey you're declaring in the WorkDone class. As an alternative you could link the ForeignKey to "ticket.c.id" but would be easier if you could use the "DeclarativeBase.metadata" for all table definitions.
Otherwise yes you need to ensure that trac.py and main.py have both been imported before you attempt to use the mappings. On Aug 13, 2011, at 4:01 PM, Tim Black wrote: > I'm getting the following error message running TurboGears 2.1.1 and > SQLAlchemy 0.7.2, using TurboGears' multiple database setup described here: > http://turbogears.org/2.1/docs/main/MultipleDatabases.html. Both databases > are SQLite3 databases; one is the main database for the TurboGears app; the > other is a Trac 0.11.4 database. Can you help me figure out what I'm doing > wrong? > > InvalidRequestError: One or more mappers failed to initialize - can't proceed > with initialization of other mappers. Original exception was: When > initializing mapper Mapper|WorkDone|work_done, expression 'ticket' failed to > locate a name ("name 'ticket' is not defined"). If this is a class name, > consider adding this relationship() to the <class > 'projects.model.main.WorkDone'> class after both dependent classes have been > defined. > > In my model/__init__.py, I import the model objects in this order (the > traceback makes me think this is the right place to work--either I need to > change the import order here, or add the relation() after the final import, > but neither of these solutions have seemed to work): > > from projects.model.trac import ticket > from projects.model.main import WorkDone > # To follow the error message's instructions, I tried adding a relation() > here, but it generated a further error; maybe I didn't get the syntax right. > > If I should add a relation immediately above, what is the right syntax? But > this also seems like a hack to add a relation() here; if I have to add a > relation() here, does that mean my current code has circular dependencies? > > Here's the rest of my relevant code (with important items in bold): > > In projects/model/trac.py, I have the following (I haven't put any relation() > or backref in this table definition, because this file is borrowed mostly > unmodified from Trac's experimental SQLAlchemy model object code, and I want > to keep it that way): > > # begin Tim's modification > from projects.model import metadata2 > metadata = metadata2 > # end Tim's modification > > # Ticket system > ticket = Table('ticket', metadata, > Column('id', Integer, primary_key=True), > Column('type', Text), > Column('time', Integer, index=True), > Column('changetime', Integer), > Column('component', Text), > Column('severity', Text), > Column('priority', Text), > Column('owner', Text), > Column('reporter', Text), > Column('cc', Text), > Column('version', Text), > Column('milestone', Text), > Column('status', Text, index=True), > Column('resolution', Text), > Column('summary', Text), > Column('description', Text), > Column('keywords', Text)) > > In projects/model/main.py, I have: > > class WorkDone(DeclarativeBase): > __tablename__ = 'work_done' > id = Column(Integer, primary_key=True) > ticket_id = Column('ticket_id', Integer, ForeignKey('ticket.id')) # > many-to-one > ticket = relation('ticket', primaryjoin=ticket_id == 'ticket.id') > > The traceback is generated by line 105 of my projects/controllers/root.py, > which reads: > > for p in DBSession.query(model.Project): > > projects/model/main.py contains: > > class Project(DeclarativeBase): > id = Column(Integer, primary_key=True) > workDone = relation('WorkDone') # one-to-many > > ...and that same class contains several properties that reference the > WorkDone model object like this one does: > > @property > def totalHours(self): > return sum([w.elapsed for w in self.workDone]) > > Thank you for any help you can offer! > > Tim > > > -- > 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. -- 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.
