Hi Massimo and howesc!
Testing again... I found a problem:
Do not return errors ( but returns no rows... ).
rows = self.db(self.tabela.nome == nome).select(self.tabela.valor,
self.tabela.valor_blob)
Returns the desired rows...
rows = self.db(self.tabela.nome == nome).select()
On Monday, June 11, 2012 10:10:18 PM UTC-3, Alex Benfica wrote:
>
> Hello people!
>
> First of all... thank you Massimo and howesc!
>
> About this question that I did and Massimo and howesc answerd on Stack
> Overflow.
> I tried to put some code there... but I could't...
>
>
> http://stackoverflow.com/questions/10940995/does-google-app-engine-projection-queries-are-supported-by-web2py
>
> I did the web2py update to trunk and some parts of my code stopped working.
> Most of problems I got where like this below, that I still don't know how
> to solve and keep it efficient, as I need to find the values by "name", not
> by id.
>
> I order to make it work, I just removed the fields I specified.
>
> Was this way (causing errors)
> self.db(self.tabela.nome == nome).select(self.tabela.valor,
> self.tabela.valor_blob, self.tabela.nome)
>
> I did that... now it selects all fields again... but works!
> self.db(self.tabela.nome == nome).select()
>
> I'm problably missing something! How can I use projection queries with
> web2py? The ID field that web2py creates are the same ID used by datastore
> on GAE?
> I have a product that I need find by name... can I query it using
> projection queries? Is that?
>
>
>
>
> rows = self.db(self.tabela.nome == nome).select(self.tabela.valor,
> self.tabela.valor_blob, self.tabela.nome)
> File "D:\Dropbox\Devel\www\web2py\gluon\dal.py", line 8161, in select
> return adapter.select(self.query,fields,attributes)
> File "D:\Dropbox\Devel\www\web2py\gluon\dal.py", line 4149, in select
> for t in fields] for item in items]
> File "C:\Program Files
> (x86)\Google\google_appengine\google\appengine\ext\db\__init__.py", line
> 2313, in next
> return self.__model_class.from_entity(self.__iterator.next())
> File "C:\Program Files
> (x86)\Google\google_appengine\google\appengine\datastore\datastore_query.py",
> line 2809, in next
> next_batch = self.__batcher.next()
> File "C:\Program Files
> (x86)\Google\google_appengine\google\appengine\datastore\datastore_query.py",
> line 2671, in next
> return self.next_batch(self.AT_LEAST_ONE)
> File "C:\Program Files
> (x86)\Google\google_appengine\google\appengine\datastore\datastore_query.py",
> line 2708, in next_batch
> batch = self.__next_batch.get_result()
> File "C:\Program Files
> (x86)\Google\google_appengine\google\appengine\api\apiproxy_stub_map.py",
> line 604, in get_result
> return self.__get_result_hook(self)
> File "C:\Program Files
> (x86)\Google\google_appengine\google\appengine\datastore\datastore_query.py",
> line 2450, in __query_result_hook
> self._batch_shared.conn.check_rpc_success(rpc)
> File "C:\Program Files
> (x86)\Google\google_appengine\google\appengine\datastore\datastore_rpc.py",
> line 1214, in check_rpc_success
> raise _ToDatastoreError(err)
> BadRequestError: cannot use projection on a property with an equality
> filter
>
