I've ran into the same problem, except I'm on GAE-Python. I want to use GeoModel on a large dataset. However, GeoModel uses "IN" queries, which means it is incompatible with cursors. Therefore, if I want to use GeoModel on very large datasets without it crapping out (or arbitrarily limiting the results), you're out of luck.
However, I wrote a work-around to this. It isn't perfect, but it get's the job done. https://www.sugarsync.com/pf/D62078_717350_6916872 On Dec 22, 12:59 am, Glenn <[email protected]> wrote: > I'm trying to find a workaround for some query cursor limitations. > Say that I have entities with date and an value which is a > multiple of ten from 0 to 100. > > I need to get paginated entities sorted by date and with the > integer field above a given threshold, along the lines of the > pseudo code: > > SELECT * FROM entity WHERE integer >= 50 ORDER BY date DESC > > What's the best way to do this? My thoughts are below. > > As the docs say, I can't use an inequality on the integer field > since then I'd have to sort by the integer first. Instead of using > integer values, I though Icould use strings: '0', '10', '20', etc., > and > then use a query like this to get entities with a value of 70 or more: > > SELECT * FROM entity WHERE integer IN [70,80,90] ORDER BY date DESC > > But as the docs say, cursors can't be obtained from queries for > entities that use contains() (i.e., IN) or even disjunctions > (value == '70' || value == '80'...). > > My question is would a multiple value property (a list) work for > this? My idea is to set the all the values up to the true entity > value, e.g., if the entity value was '40', then the MVP would be > ['0', '10', '20', '30', '40']. Then if the threshold was 20, > then entities such as this would (I believe) be returned by a query > like > > SELECT * FROM entity WHERE value == '20' ORDER BY date DESC > > Can you obtain a cursor from such a query or is there a better way? > > Thanks, > Glenn -- 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.
