Not sure if this is relevant? As you might have guessed from my posts,
I am at the 'waving a dead chicken' around stage of debugging.
pjjH
(Pdb) import pickle
(Pdb) print pickle.dumps(m)
*** PicklingError: Can't pickle <class
'sqlalchemy.orm.properties.Comparator'>: it's not found as
sqlalchemy.orm.properties.Comparator
(Pdb) import sqlalchemy.orm.properties.Comparator
*** ImportError: No module named Comparator
(Pdb) import sqlalchemy.orm.properties
(Pdb) print pickle.dumps(m)
*** PicklingError: Can't pickle <class
'sqlalchemy.orm.properties.Comparator'>: it's not found as
sqlalchemy.orm.properties.Comparator
On Apr 3, 1:51 pm, "phrrn...@googlemail.com" <phrrn...@googlemail.com>
wrote:
> I don't see any output from it at all. I am calling it after importing
> everything but before making any queries. The mapper registry looks
> unsurprising (albeit based on a guess of what it does)
>
> pjjH
>
> from sqlalchemy.orm import compile_mappers
>
> s = MySession(bind=e)
>
> print compile_mappers()
> q = s.query(Dataserver)
>
> (Pdb) p _mapper_registry
> <WeakKeyDictionary at 139496364>
> (Pdb) p _mapper_registry.keys()
> [<Mapper at 0x8669e6c; _PrimaryKeyElement>, <Mapper at 0x866eb0c;
> _ForeignKeyElement>, <Mapper at 0x868272c; _ForeignKey>, <Mapper at
> 0x861fe8c; Attribute>, <Mapper at 0x868ea0c; Sample>, <Mapper at
> 0x8676bac; _Index>, <Mapper at 0x865ca6c; _IndexElement>, <Mapper at
> 0x861f40c; _ExtendedProperty>, <Mapper at 0x8687c0c; Dataserver>,
> <Mapper at 0x868786c; Catalog>, <Mapper at 0x868730c; DatabaseTable>,
> <Mapper at 0x867da0c; _PrimaryKey>]
> (Pdb) n>
> /usr/local/python-2.5.1/lib/python2.5/site-packages/SQLAlchemy-0.5.2-py2.5.egg/sqlalchemy/orm/__init__.py(842)compile_mappers()
>
> -> m.compile()
> (Pdb) p m
> <Mapper at 0x8669e6c; _PrimaryKeyElement>
> (Pdb) p repr(m)
> '<Mapper at 0x8669e6c; _PrimaryKeyElement>'
> (Pdb) p str(m)
> 'Mapper|_PrimaryKeyElement|widened_sp_primarykeys'
>
> On Apr 3, 1:37 pm, "Michael Bayer" <mike...@zzzcomputing.com> wrote:
>
> > what does compile_mappers() say? can you call this mapper, and at the
> > same time all mappers within the entire application have been called ?
>
> > phrrn...@googlemail.com wrote:
>
> > > I copied the list of import statements from the module file
> > > (deshaw.dbo.chimera) to the driver file. The driver file also has a
> > > line:
> > > from deshaw.dbo.chimera import *
>
> > > Note that this is happening with a particular class, DatabaseTable,
> > > *not* with other classes I have declared and mapped such as
> > > Dataserver. Interestingly, the DatabaseClass works when I comment out
> > > a bunch of relations:
>
> > > mapper(DatabaseTable, tables, properties = {
> > > # 'attributes' : relation(Attribute, lazy=False,
> > > order_by = asc(Attribute.ORDINAL_POSITION)),
> > > # 'primary_key' : relation(_PrimaryKey, uselist=False,
> > > lazy=False), # At most one PK is allowed.
> > > # 'indexes' : relation(_Index,lazy=False),
> > > # 'foreign_keys' : relation(_ForeignKey,
> > > lazy=False)
> > > })
>
> > > I experimented with adding the properties later on after everything
> > > else had been defined but still get the same error
>
> > > class_mapper(DatabaseTable).add_properties({
> > > # 'attributes' : relation(Attribute, lazy=False,
> > > order_by = asc(Attribute.ORDINAL_POSITION)),
> > > # 'primary_key' : relation(_PrimaryKey, uselist=False,
> > > lazy=False), # At most one PK is allowed.
> > > # 'indexes' : relation(_Index,lazy=False),
> > > # 'foreign_keys' : relation(_ForeignKey,
> > > lazy=False)
> > > })
>
> > > How do I find out what is special about 'DatabaseTable' or, more
> > > precisely, the properties I am trying to define on it. I tried putting
> > > compile_mappers() in both the module and the driver but it has no
> > > impact. I assume that one of 'attributes', 'primary_key', 'indexes' or
> > > 'foreign_keys' is already in use .. OK. Let me try that:
>
> > > class_mapper(DatabaseTable).add_properties({
> > > # 'apple' : relation(Attribute, lazy=False, order_by
> > > = asc(Attribute.ORDINAL_POSITION)),
> > > # 'banana' : relation(_PrimaryKey, uselist=False,
> > > lazy=False), # At most one PK is allowed.
> > > 'pear' : relation(_Index,lazy=False),
> > > # 'kiwi' : relation(_ForeignKey, lazy=False)
> > > })
>
> > > No, didn't do anything. Let's try with lazy=True. OK that works. Let's
> > > try lazy=True with the original names. OK. That works also. So the
> > > problem appears to be with setting lazy=True for these properties.
>
> > > What is the debugging incantation to debug the orm mapping? Or do you
> > > have any advice on how to proceed from here?
>
> > > thanks,
>
> > > pjjH
>
> > > On Apr 2, 9:20 pm, Michael Bayer <zzz...@gmail.com> wrote:
> > >> make sure everything that's needed is imported, and that you arent
> > >> suppressing any exceptions which occur when the mappers first compile
> > >> themselves. try calling compile_mappers() to force the issue.
>
> > >> On Apr 2, 8:19 pm, "phrrn...@googlemail.com" <phrrn...@googlemail.com>
> > >> wrote:
>
> > >> > This code works when executed within a if __name__ == '__main__'
> > >> > block in the .py that contains the model:
>
> > >> > s = MySession(bind=e)
> > >> > q = s.query(DatabaseTable).filter(DatabaseTable.TABLE_CAT=='credit')
> > >> > for i in q:
> > >> > print i
>
> > >> > However, if I take it out and put it in a separate file, I get an
> > >> > error like this. I hope that this is something simple that I am doing
> > >> > wrong?
> > >> > pjjH
>
> > >> > Traceback (most recent call last):
> > >> > File "H:\work\base_python\python\chimera_driver.py", line 14, in
> > >> > <module>
> > >> > for i in q:
> > >> > File "C:\PROGRA~1\Python25\lib\site-packages\sqlalchemy-0.5.2-
> > >> > py2.5.egg\sqlalchemy\orm\query.py", line 1276, in __iter__
> > >> > context = self._compile_context()
> > >> > File "C:\PROGRA~1\Python25\lib\site-packages\sqlalchemy-0.5.2-
> > >> > py2.5.egg\sqlalchemy\orm\query.py", line 1718, in _compile_context
> > >> > entity.setup_context(self, context)
> > >> > File "C:\PROGRA~1\Python25\lib\site-packages\sqlalchemy-0.5.2-
> > >> > py2.5.egg\sqlalchemy\orm\query.py", line 1972, in setup_context
> > >> > column_collection=context.primary_columns
> > >> > File "C:\PROGRA~1\Python25\lib\site-packages\sqlalchemy-0.5.2-
> > >> > py2.5.egg\sqlalchemy\orm\interfaces.py", line 580, in setup
> > >> > self.__get_context_strategy(context, path +
> > >> > (self.key,)).setup_query(context, entity, path, adapter, **kwargs)
> > >> > File "C:\PROGRA~1\Python25\lib\site-packages\sqlalchemy-0.5.2-
> > >> > py2.5.egg\sqlalchemy\orm\interfaces.py", line 566, in __get_context_
> > >> > strategy
> > >> > return self.strategy
> > >> > AttributeError: 'RelationProperty' object has no attribute 'strategy'
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