Hi Alex. Since you can't query for these, you'll have to page through all entities. This will be much easier once cursors are added, but until then, you can either use a JDO extent or follow the paging tips listed in http://code.google.com/appengine/articles/paging.html. You can use this in conjunction with task queues to do this in the background.
- Jason On Thu, Oct 22, 2009 at 2:43 AM, Alexander Arendar < alexander.aren...@gmail.com> wrote: > > Hi Jason, > > maybe my question is a trivial for you but still: > how melodramatically should I detect when the value is NOT set? > As you already explained i can't use ==null. What should I use > instead? > > Sincerely, > Alex > > On Oct 21, 9:36 pm, "Jason (Google)" <apija...@google.com> wrote: > > No. If an entity does not have a value set for a particular property > (null > > IS a value, different from <missing>), then it won't appear in any query > > results involving that property. You'll need to continue sifting through > > every entity to see if a value is set, and if not, setting it directly. > > - Jason > > > > On Mon, Oct 19, 2009 at 6:09 AM, Prashant <antsh...@gmail.com> wrote: > > > hi, > > > > > i added a new column to my data table, as it is newly added it is > showing > > > <missing> as column values in datastore. now i want to initialize those > > > <missing> values to some value, say 0. how do i do that > programmatically? i > > > tried using "column == null" as filter but that doesn't work. > > > > > > > --~--~---------~--~----~------------~-------~--~----~ 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 google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~----------~----~----~----~------~----~------~--~---
