I have tired to implement a many to many relationship from the online
documentation and the example attached in the previous Many to Many
thread but to no avail.
I am trying to following:
CREATE TABLE roles (
rl_id BIGSERIAL NOT NULL PRIMARY KEY,
rl_name TEXT NOT NULL,
rl_desc TEXT NOT NULL,
UNIQUE(rl_name)
) WITHOUT OIDS;
CREATE TABLE users (
usr_id BIGSERIAL NOT NULL PRIMARY KEY,
usr_logon TEXT NOT NULL,
usr_name TEXT NOT NULL,
usr_pp TEXT NOT NULL,
UNIQUE(usr_logon)
) WITHOUT OIDS;
CREATE TABLE users_x_roles (
usr_id BIGINT NOT NULL,
rl_id BIGINT NOT NULL,
PRIMARY KEY(usr_id,rl_id)
) WITHOUT OIDS;
roles = Table('roles', db,
Column('rl_id', Integer, Sequence('roles_id_seq', optional=False),
primary_key=True),
Column('rl_name', String, nullable=False),
Column('rl_desc', String, nullable=False))
users_x_roles = Table('users_x_roles', db,
Column('usr_id', Integer, ForeignKey('users.usr_id'), nullable=False),
Column('rl_id', Integer, ForeignKey('roles.rl_id'), nullable=False))
users = Table('users', db,
Column('usr_id', Integer, Sequence('users_id_seq',optional=False),
primary_key=True),
Column('usr_logon', String, nullable=False),
Column('usr_pp', String, nullable=False),
Column('usr_name', String, nullable=False))
assign_mapper(Role, tables.roles, properties={
'rl_id': tables.roles.c.rl_id,
'name': tables.roles.c.rl_name,
'desc': tables.roles.c.rl_desc,})
assign_mapper(User, tables.users, properties={
'usr_id': tables.users.c.usr_id,
'logon': tables.users.c.usr_logon,
'pp': tables.users.c.usr_pp ,
'name': tables.users.c.usr_name,
'_roles': relation(Role, secondary=tables.users_x_roles,
primaryjoin=tables.users.c.usr_id==tables.users_x_roles.c.usr_id,
secondaryjoin=tables.users_x_roles.c.rl_id==tables.roles.c.rl_id,
lazy=False),})
Then when running the following:
u = User.mapper.get(1)
The following exception is raised:
/usr/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/sqlalchemy/mapping/mapper.py
in init(self, *args, **kwargs)
224 except TypeError, msg:
225 # re-raise with the offending class
name added to help in debugging
--> 226 raise TypeError, '%s.%s'
%(self.__class__.__name__, msg)
227 # override oldinit, insuring that its not already one of our
228 # own modified inits
TypeError: User.len() of unsized object
I'm at a loss as to what I'm doing incorrectly. Any suggestions?
---- FULL TRACE ----
exceptions.TypeError Traceback (most
recent call last)
/usr/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/sqlalchemy/mapping/mapper.py
in get(self, *ident)
273 key = objectstore.get_id_key(ident, self.class_)
274 #print "key: " + repr(key) + " ident: " + repr(ident)
--> 275 return self._get(key, ident)
276
277 def _get(self, key, ident=None):
/usr/lib/python2.4/site-packages/SQLAlchemy-
0.1.2-py2.4.egg/sqlalchemy/mapping/mapper.py in _get(self, key, ident)
287 i += 1
288 try:
--> 289 return self.select(self._get_clause, params=params)[0]
290 except IndexError:
291 return None
/usr/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/sqlalchemy/mapping/mapper.py
in select(self, arg, **kwargs)
450 return self.select_statement(arg, **kwargs)
451 else:
--> 452 return self.select_whereclause (arg, **kwargs)
453
454 def select_whereclause(self, whereclause=None,
params=None, **kwargs):
/usr/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/sqlalchemy/mapping/mapper.py
in select_whereclause(self, whereclause, params, **kwargs)
455 statement = self._compile(whereclause, **kwargs)
456 if params is not None:
--> 457 return self.select_statement(statement, **params)
458 else:
459 return self.select_statement(statement)
/usr/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/sqlalchemy/mapping/mapper.py
in select_statement(self, statement, **params)
468 def select_statement(self, statement, **params):
469 statement.use_labels = True
--> 470 return self.instances(statement.execute(**params))
471
472 def select_text(self, text, **params):
/usr/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/sqlalchemy/mapping/mapper.py
in instances(self, cursor, *mappers, **kwargs)
252 if row is None:
253 break
--> 254 self._instance(row, imap, result)
255 i = 0
256 for m in mappers:
/usr/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/sqlalchemy/mapping/mapper.py
in _instance(self, row, imap, result, populate_existing)
750 instance = self.extension.create_instance(self,
row, imap, self.class_)
751 if instance is None:
--> 752 instance = self.class_(_mapper_nohistory=True)
753 imap[identitykey] = instance
754 isnew = True
/usr/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/sqlalchemy/mapping/mapper.py
in init(self, *args, **kwargs)
224 except TypeError, msg:
225 # re-raise with the offending class
name added to help in debugging
--> 226 raise TypeError, '%s.%s'
%(self.__class__.__name__, msg)
227 # override oldinit, insuring that its not already
one of our
228 # own modified inits
TypeError: User.len() of unsized object
