Good idea. I've already done something similar to allow for full text search. I can append the rating to the timestamp to create a longer numeric value that can be sorted.
Thanks! On Jun 10, 4:40 am, dflorey <[email protected]> wrote: > When I face such a problem I try to solve them with "synthetic" > properties. > If you want to be able to find the top ratings from a given timeframe > you could concat timestamp+rating and store this into a single > property and do a query on this property restricting to a certain > timeframe with converting dates to timestamp and doing some > < and > sort descending within a single query. > > On Jun 9, 4:34 pm, Billy <[email protected]> wrote: > > > > > Hi, I'm trying to do a relatively simple query using appengine(1.3.3) > > and JDO. Basically I want to obtain the "top 10 ranked entities for > > the last year". Assume I have an entity FOO and properties startDate > > and rating ...I would normally do this using a query like below: > > > select from FOO where startDate >= someDate order by rating desc range > > 0,10; > > > I understand however that inequality filters must be specified first > > in any sort ordering and so this does not work. So the only way I > > know to accomplish this is to query for all FOOs where startDate >= > > someDate and then sort them in-memory by rating. This could work, but > > I anticipate a large amount of data in FOO and so I don't want to load > > 10K records into memory to sort them when I really only the top 10 of > > them. > > > Any other ideas on how to workaround this limitation? Thanks for your > > help... -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. 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-java?hl=en.
