Hi Charlie, What do you mean by "not totally working"? Also, you may have better luck asking this in the google-appengine-java group.
-Nick Johnson On Sat, Jun 20, 2009 at 3:36 PM, Charlie Zhu <[email protected]> wrote: > > Thank you, Nick, > > I have written code as below with low level API to delete the entry. > It runs without error but seems not totally working. And thanks god > that data suddenly appeared at Data Viewer and problem resolved. > > Code pasted here and hope it useful for others > > import com.google.appengine.api.datastore.DatastoreService; > import com.google.appengine.api.datastore.DatastoreServiceFactory; > import com.google.appengine.api.datastore.Entity; > import com.google.appengine.api.datastore.Query; > > public void doGet(HttpServletRequest req, HttpServletResponse resp) > throws IOException { > String tbname = req.getParameter("tbname"); > if(tbname!=null) > { > DatastoreService datastore = > DatastoreServiceFactory.getDatastoreService(); > > // Or perform a query > Query query = new Query(tbname); > for (Entity taskEntity : > datastore.prepare(query).asIterable()) { > datastore.delete(taskEntity.getKey()); > } > } > } > > > Regards, > Charlie > > On Jun 17, 11:58 pm, "Nick Johnson (Google)" <[email protected]> > wrote: > > Hi Charlie, > > > > Your easiest option here is probably to upload an alternate major version > of > > your app with the old schema, and use that to retrieve and fix the faulty > > entit(y|ies). Alternate approaches include using the low level datastore > > API, or uploading a Python version that uses the low level API or > > db.Expando. > > > > -Nick Johnson > > > > > > > > > > > > On Wed, Jun 17, 2009 at 9:15 AM, Charlie Zhu <[email protected]> > wrote: > > > > > Hi, > > > > > I have tried all ways I known to delete some schema changing caused > > > error Entities and failed. > > > > > 1. Delete on Data Viewer on the console. > > > Data Viewer shows "No Data Yet." > > > > > 2. Delete by code > > > Below is part of the codes: > > > Query q = pm.newQuery(CDKFingerprint.class); > > > List<CDKFingerprint> results2; > > > results2 = (List<CDKFingerprint>) q.execute(); > > > pm.deletePersistentAll(results2); > > > But that cause server error: > > > java.lang.NullPointerException: Datastore entity with kind > > > CDKFingerprint and key CDKMol(c=cc=cc=c)/CDKFingerprint(1) has a null > > > property named bits_count. This property is mapped to > > > cdkhelper.CDKFingerprint.bits_count, which cannot accept null values. > > > ... > > > at org.datanucleus.jdo.JDOPersistenceManager.deletePersistentAll > > > (JDOPersistenceManager.java:795) > > > ... > > > > > 3. Assign values to the NULL field then delete > > > The code > > > for(CDKFingerprint r: results2) { > > > r.bits_count = 0; > > > pm.makePersistent(r); > > > } > > > And server error again > > > java.lang.NullPointerException: Datastore entity with kind > > > CDKFingerprint and key CDKMol(c=cc=cc=c)/CDKFingerprint(1) has a null > > > property named bits_count. This property is mapped to > > > cdkhelper.CDKFingerprint.bits_count, which cannot accept null values. > > > ... > > > at org.datanucleus.store.appengine.query.StreamingQueryResult > > > $AbstractListIterator.hasNext(StreamingQueryResult.java:205) > > > ... > > > > > Having no idea and hoping help. > > > > > Regards, > > > Charlie > > > > -- > > Nick Johnson, App Engine Developer Programs Engineer > > Google Ireland Ltd. :: Registered in Dublin, Ireland, Registration > Number: > > 368047 > > > -- Nick Johnson, App Engine Developer Programs Engineer Google Ireland Ltd. :: Registered in Dublin, Ireland, Registration Number: 368047 --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" 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?hl=en -~----------~----~----~----~------~----~------~--~---
