The datastore statistics API can return the number of entities of a particular kind, but you will have to issue a query to get all entities having a specific value for a property.
- Jason On Wed, Oct 28, 2009 at 3:29 AM, Patrizio Munzi <[email protected]>wrote: > Hi Jason, > > Thanks for your answer. > However I forgot to specify that I'd like to know the number of entities of > a specific kind which have a specific value in one of its field (for example > number of Student which attend a specific course). > It looks like Statistics don't fit this aim, not that they should though. > > BR, > Patrizio > > > Jason (Google) wrote: > > You can also use the new datastore statistics API, which is probably faster > although I haven't timed this myself: > > http://code.google.com/appengine/docs/java/datastore/stats.html > > - Jason > > On Mon, Oct 26, 2009 at 6:42 AM, Patrizio Munzi > <[email protected]>wrote: > >> >> Hi all, >> >> what's the best way to know the number of entities of a specific kind >> saved into the DS? >> Of course I'd like to know the optimized way, without retrieving all the >> objects. >> >> Thanks >> >> >> > > > > -- > > *Patrizio Munzi* > Product Specialist > Viale Bruno Buozzi, 19 - 00197 Roma (Italy) > tel: +39 06 4543 3540 > fax: +39 06 4543 3587 > mobile: +39 393 7195 164 > mail: [email protected] > web: http://www.eris4.com > skype: eris4_munzi > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
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