I haven't used projections in queries, but I was just reading the docs and noted the following about indexes.
projectionList or tuple of names of properties to return. Only entities possessing the specified properties will be returned. If not specified, entire entities are returned by default. Projection queries<https://developers.google.com/appengine/docs/python/datastore/queries#Projection_Queries> are faster and cheaper than those that return complete entitites. *Note:* Specifying this parameter may change the query's index requirements. Maybe you have added the projection arg and are encountering an index that hasn't been rebuilt. That could be one explanation. The other thing to check would be if the missing records have values for the properties specified in the projection. Rgds T On Tuesday, June 19, 2012 10:35:32 PM UTC+8, Christopher Ramírez wrote: > > Yes it happens on both servers. > > On Monday, June 18, 2012 11:01:08 AM UTC-6, Alfred Fuller wrote: >> >> Does this happen in both the dev_appserver and production? >> >> On Fri, Jun 15, 2012 at 10:28 AM, Christopher Ramírez < >> [email protected]> wrote: >> >>> I was trying to use projection queries, but I had extrange issues using >>> them. >>> >>> I'm trying to use them like this: >>> offset_group = Clients.all( \ >>> projection=('name', 'sex', 'birth_date', 'email', 'discount') >>> ).order('-__key__').fetch(limit=10, offset=skip_recs) >>> >>> The above code is supposed to bring me the last 10 clients. But actually >>> it does not return the last 10 (actually returns fewer and the actual last >>> record is not included). Also the results seems alternated or maybe >>> even/odd are skipped. If I take off projection param, the result is as >>> spected: >>> offset_group = Clients.all().order('-__key__').fetch(limit=10, >>> offset=skip_recs) >>> >>> I do not know if this is a bug in projection queries or they have to be >>> used in a different way. Please help me. I would like to use projection >>> queries because they are really fast! >>> >>> Kind Regards, >>> Christopher Ramírez >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Google App Engine" group. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msg/google-appengine/-/Ahgw_iP_mukJ. >>> To post to this group, send email to [email protected]. >>> To unsubscribe from this group, send email to >>> [email protected]. >>> For more options, visit this group at >>> http://groups.google.com/group/google-appengine?hl=en. >>> >> >> -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/WmBg8skHXTAJ. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
