It would be good to have the ability to do this from within the GUI. Other database management tools have "empty table" options, so a "delete all of this Kind" feature would be appropriate.
On Jan 22, 12:59 pm, John Patterson <[email protected]> wrote: > Here is the code I use to delete one kind at a time - it batches the > keys into Lists of 100 to avoid datastore exceptions. Iterables is > from Google collections. > > Query query = new Query(kind); > query.setKeysOnly(); > DatastoreService datastore = ... > Iterable<Entity> entityIterator = > datastore.prepare(query).asIterable(); > Iterable<Key> keyIterator = > Iterables.transform(entityIterator, > new Function<Entity, Key>() > { > public Key apply(Entity arg0) > { > return arg0.getKey(); > } > }); > > Iterable<List<Key>> partitioned = > Iterables.partition(keyIterator, 100); > for (List<Key> sublist : partitioned) > { > datastore.delete(sublist); > } > > On 22 Jan 2010, at 15:10, mete wrote: > > > > > Suppose I have a class A and I have stored some instance of it in the > > datastore. Then I change it, but I keep the name. How I can delete all > > the previous data in the datastore, if I simply do a query and use > > deleteAll, it gives an error (I guess because I changed the name of > > some fields). Thank you. > > > Mete > > > -- > > 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 > > athttp://groups.google.com/group/google-appengine-java?hl=en > > . -- 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.
