here's the new error message in the latest trunk:
InvalidRequestError: Can't issue count() for multiple types of objects
or columns. Construct the Query against a single element as the thing
to be counted, or for an actual row count use
Query(func.count(somecolumn)) or query.values(func.count(somecolumn))
instead.
On Nov 8, 2008, at 4:03 PM, Michael Bayer wrote:
>
> oh sorry, also count() is meant to count instances of a single kind of
> object. So in fact you should be saying:
>
> session.query(UserRss).join(Rss, item).count()
>
>
> On Nov 8, 2008, at 3:03 PM, Greg wrote:
>
>>
>>
>> This following request works fine and produce the result I was
>> expecting session.query(UserRss, Rss, Item).join([Rss, Item]). But
>> count doesn't work. Is it a bug, or did I miss something ?
>>
>>>>> str(session.query(UserRss, Rss, Item).join([Rss, Item]).count())
>>
>> Traceback (most recent call last):
>> File "<console>", line 1, in <module>
>> File "/opt/local/lib/python2.5/site-packages/SQLAlchemy-0.5.0rc3-
>> py2.5.egg/sqlalchemy/orm/query.py", line 1251, in count
>> return self._col_aggregate(sql.literal_column('1'),
>> sql.func.count,
>> nested_cols=list(self._only_mapper_zero().primary_key))
>> File "/opt/local/lib/python2.5/site-packages/SQLAlchemy-0.5.0rc3-
>> py2.5.egg/sqlalchemy/orm/query.py", line 241, in _only_mapper_zero
>> raise sa_exc.InvalidRequestError("This operation requires a Query
>> against a single mapper.")
>> InvalidRequestError: This operation requires a Query against a single
>> mapper.
>>
>> Thanks.
>> Greg
>>
>>
>>>
>
>
> >
--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---
