I am trying to go through the mapping tutorial in 0.4.2p3 for association objects. I get an error about "Could not assemble any primary key columns for mapped table 'association'" when attempting to map the association table itself. This is straight out of the Mapping Configuration docs that comes with the distribution...
Any thoughts on where things are going awry? Here's my complete code: from sqlalchemy import create_engine, \ Table, Column, Integer, String, \ MetaData, ForeignKey from sqlalchemy.orm import relation, sessionmaker, mapper engine = create_engine('sqlite:///:memory:', echo=True) metadata = MetaData(); left_table = Table('left', metadata, Column('id', Integer, primary_key=True)) right_table = Table('right', metadata, Column('id', Integer, primary_key=True)) association_table = Table('association', metadata, Column('left_id', Integer, ForeignKey('left.id')), Column('right_id', Integer, ForeignKey('right.id')), Column('data', String(50)) ) class Parent(object): pass class Association(object): pass class Child(object): pass mapper( Parent, left_table, properties={ 'children':relation(Association) }) mapper( Association, association_table, properties={ 'child':relation(Child) # <--- chokes here }) mapper( Child, right_table) metadata.create_all( engine ) And here is what I get: $ python -i posting.py Traceback (most recent call last): File "posting.py", line 31, in <module> 'child':relation(Child) # <--- chokes here File "/tmp/SQLAlchemy-0.4.2p3/lib/sqlalchemy/orm/__init__.py", line 544, in mapper return Mapper(class_, local_table, *args, **params) File "/tmp/SQLAlchemy-0.4.2p3/lib/sqlalchemy/orm/mapper.py", line 160, in __init__ self._compile_pks() File "/tmp/SQLAlchemy-0.4.2p3/lib/sqlalchemy/orm/mapper.py", line 428, in _compile_pks raise exceptions.ArgumentError("Could not assemble any primary key columns for mapped table '%s'" % (self.mapped_table.name)) sqlalchemy.exceptions.ArgumentError: Could not assemble any primary key columns for mapped table 'association' >>> --~--~---------~--~----~------------~-------~--~----~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---