Hi,
I'm trying the single table inheritance example (see the attachment)
from the 0.2 docs, and it fails with the following traceback:
Traceback (most recent call last):
File "single.py", line 37, in ?
manager_mapper = mapper(Manager, inherits=employee_mapper,
polymorphic_identity='manager')
File "f:\lib\python\pyfr\__init__.py", line 49, in mapper
File "build\bdist.win32\egg\sqlalchemy\orm\mapper.py", line 139, in
__init__
File "build\bdist.win32\egg\sqlalchemy\sql.py", line 39, in join
File "build\bdist.win32\egg\sqlalchemy\sql.py", line 1017, in __init__
File "build\bdist.win32\egg\sqlalchemy\sql.py", line 1037, in
_match_primaries
AttributeError: 'NoneType' object has no attribute 'foreign_keys'
ideas ?
from sqlalchemy import *
metadata = DynamicMetaData()
class Employee(object):
def __init__(self, name):
self.name = name
def __repr__(self):
return self.__class__.__name__ + " " + self.name
class Manager(Employee):
def __init__(self, name, manager_data):
self.name = name
self.manager_data = manager_data
def __repr__(self):
return self.__class__.__name__ + " " + self.name + " " + self.manager_data
class Engineer(Employee):
def __init__(self, name, engineer_info):
self.name = name
self.engineer_info = engineer_info
def __repr__(self):
return self.__class__.__name__ + " " + self.name + " " + self.engineer_info
employees_table = Table('employees', metadata,
Column('employee_id', Integer, primary_key=True),
Column('name', String(50)),
Column('manager_data', String(50)),
Column('engineer_info', String(50)),
Column('type', String(20))
)
employee_mapper = mapper(Employee, employees_table, polymorphic_on=employees_table.c.type)
manager_mapper = mapper(Manager, inherits=employee_mapper, polymorphic_identity='manager')
engineer_mapper = mapper(Engineer, inherits=employee_mapper, polymorphic_identity='engineer')
metadata.connect('sqlite://', echo=True)
