ok, i committed a very small change and applied several layers of
scotch tape to your example and it is roughly working. attached is a
test script which documents a few of the quirks with this sort of
thing right now. I have in mind some refactorings to make mapper
inheritance a little stronger, after working with this example.
from sqlalchemy import *
import sqlalchemy
engine = create_engine('sqlite://', echo=True)
foo = Table('foo', engine,
Column('id', Integer, primary_key=True),
Column('data', String(20)),
).create()
bar = Table('bar', engine,
Column('id', Integer, ForeignKey('foo.id'), primary_key=True),
).create()
foo_bar = Table('foo_bar', engine,
Column('foo_id', Integer, ForeignKey('foo.id')),
Column('bar_id', Integer, ForeignKey('bar.id'))).create()
class Foo(object):
def __init__(self, data=None):
self.data = data
def __str__(self):
return "Foo(%s)" % self.data
def __repr__(self):
return str(self)
Foo.mapper = mapper(Foo, foo)
class Bar(Foo):
def __str__(self):
return "Bar(%s)" % self.data
Bar.mapper = mapper(Bar, bar, inherits=Foo.mapper, properties = {
# this is needed at the moment if the join
# columns in 'foo' and 'bar' are not the same name
#'id':[bar.c.bid, foo.c.id]
})
# the join conditions come out nicer if you specify them explicitly
Bar.mapper.add_property('foos', relation(Foo.mapper, foo_bar, primaryjoin=bar.c.id==foo_bar.c.bar_id, secondaryjoin=foo_bar.c.foo_id==foo.c.id, lazy=False))
# but this works too
#Bar.mapper.add_property('foos', relation(Foo.mapper, foo_bar, lazy=False))
b = Bar('barfoo')
objectstore.commit()
b.foos.append(Foo('subfoo1'))
b.foos.append(Foo('subfoo2'))
objectstore.commit()
objectstore.clear()
l =b.mapper.select()
print l[0]
print l[0].foos
On Feb 25, 2006, at 6:37 PM, Florian Boesch wrote:
I require that kind of thing, so I've assembled a little testcode
to demonstrate
the problems.
Below is the vanilla many to many thing that doesn't error upon
defintion (with
one minor glitch at the mapper, see #comments)
from sqlalchemy import *
from sqlalchemy.ext.proxy import ProxyEngine
engine = ProxyEngine()
foo = Table('foo', engine,
Column('id', Integer, primary_key=True))
bar = Table('bar', engine,
Column('id', Integer, primary_key=True))
foo_bar = Table('foo_bar', engine,
Column('foo_id', Integer, ForeignKey('foo.id')),
Column('bar_id', Integer, ForeignKey('bar.id')))
class Foo(object): pass
Foo.mapper = mapper(Foo, foo)
class Bar(object): pass
Bar.mapper = mapper(Bar, bar)
# Bar.mapper.add_property('foos', relation(Foo, foo_bar))
# ==> sqlalchemy.exceptions.ArgumentError: relation(class, table,
**kwargs) is
# deprecated. Please use relation(class, **kwargs) or relation
(mapper,
**kwargs).
Bar.mapper.add_property('foos', relation(Foo.mapper, foo_bar))
Now when I throw in inheritance as in
bar = Table('bar', engine,
Column('id', Integer, ForeignKey('foo.id'), primary_key=True))
Bar.mapper = mapper(Bar, bar, inherits=Foo.mapper)
and then try to
Bar.mapper.add_property('foos', relation(Foo.mapper, foo_bar))
I get:
Traceback (most recent call last):
File "testalchemy.py", line 23, in ?
Bar.mapper.add_property('foos', relation(Foo.mapper, foo_bar))
File
"/usr/local/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/
sqlalchemy/mapping/mapper.py",
line 195, in add_property
prop.init(key, self)
File
"/usr/local/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/
sqlalchemy/mapping/mapper.py",
line 777, in init
self.do_init(key, parent)
File
"/usr/local/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/
sqlalchemy/mapping/properties.py",
line 191, in do_init
self._compile_synchronizers()
File
"/usr/local/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/
sqlalchemy/mapping/properties.py",
line 583, in _compile_synchronizers
self.primaryjoin.accept_visitor(processor)
File
"/usr/local/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/
sqlalchemy/sql.py",
line 749, in accept_visitor
c.accept_visitor(visitor)
File
"/usr/local/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/
sqlalchemy/sql.py",
line 819, in accept_visitor
visitor.visit_binary(self)
File
"/usr/local/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/
sqlalchemy/mapping/properties.py",
line 969, in visit_binary
self.func(binary)
File
"/usr/local/lib/python2.4/site-packages/SQLAlchemy-0.1.2-py2.4.egg/
sqlalchemy/mapping/properties.py",
line 575, in compile
raise AssertionError("assert failed")
sqlalchemy.exceptions.AssertionError: assert failed
(a sidenote, assert failed isn't a very clever assert line :D)
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