If following operation throws an exception,we can not rollback the first transaction, because it is already committed. What I can think of right now is, you can manually delete it. but it is not the genuine solution.
Why don't you create owned relation between these two table? Tell me about your thoughts? Regards, Kartik 2010/12/16 Liang Ding <[email protected]> > Hi, kartik. > It works, but how can I rollback the 'first transaction' if the following > operations throws an exception? > > 2010/12/16 kartik kudada <[email protected]> > >> You can not operate on two entities in single transaction unless both are >> entity groups. >> First delete CityNum in one transaction and then delete ScheduleProcess >> in different transaction, >> >> >> >> >> >> >> >> >> 2010/12/16 EtuO <[email protected]> >> >>> Caused by: java.lang.IllegalArgumentException: can't operate on >>> >>> multiple entity groups in a single transaction. found both Element { >>> type: "CityNum" >>> name: "013001" >>> } >>> and Element { >>> type: "ScheduleProcess" >>> name: "013001" >>> } >>> >>> at >>> >>> com.google.appengine.api.datastore.DatastoreApiHelper.translateError(DatastoreApiHelper.java: >>> 36) >>> at com.google.appengine.api.datastore.DatastoreApiHelper >>> $1.convertException(DatastoreApiHelper.java:98) >>> at >>> com.google.appengine.api.utils.FutureWrapper.get(FutureWrapper.java: >>> 69) >>> at com.google.appengine.api.datastore.FutureHelper >>> $CumulativeAggregateFuture.get(FutureHelper.java:136) >>> at com.google.appengine.api.datastore.FutureHelper >>> $TxnAwareFuture.get(FutureHelper.java:213) >>> at >>> com.google.appengine.api.utils.FutureWrapper.get(FutureWrapper.java: >>> 67) >>> at >>> >>> com.google.appengine.api.datastore.FutureHelper.getInternal(FutureHelper.java: >>> 71) >>> at >>> >>> com.google.appengine.api.datastore.FutureHelper.quietGet(FutureHelper.java: >>> 58) >>> at >>> >>> com.google.appengine.api.datastore.DatastoreServiceImpl.get(DatastoreServiceImpl.java: >>> 55) >>> at >>> >>> org.datanucleus.store.appengine.RuntimeExceptionWrappingDatastoreService.get(RuntimeExceptionWrappingDatastoreService.java: >>> 64) >>> ... 86 more >>> >>> 实现类代码： >>> /** >>> * @see >>> >>> org.ertuo.taoplugin.facade.TransactionOperation#nestTrans(java.lang.Object[]) >>> */ >>> public void nestTrans(Object... objects) { >>> String id = (String) objects[0]; >>> CityNum cn = cityNumDao.get(id); >>> ScheduleProcess sp = scheduleDao.get(id); >>> cityNumDao.delete(cn); >>> scheduleDao.delete(sp); >>> logger.info("id[" + id + "]对应的城市和任务删除完毕"); >>> } >>> >>> 接口代码： >>> /** >>> * 事务性操作接口 >>> * @author mo.duanm >>> * @version $Id: TransactionOperation.java, v 0.1 2010-12-16 下午 >>> 05:22:23 mo.duanm Exp $ >>> */ >>> public interface TransactionOperation { >>> >>> /** >>> * 嵌套事务 >>> * @param objects >>> */ >>> @Transactional >>> public void nestTrans(Object... objects); >>> >>> -- >>> 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]<google-appengine-java%[email protected]> >>> . >>> For more options, visit this group at >>> http://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]<google-appengine-java%[email protected]> >> . >> For more options, visit this group at >> http://groups.google.com/group/google-appengine-java?hl=en. >> > > > > -- > My Blog: http://blog.csdn.net/DL88250 > -------------------------------------------------------- > Open Source, Open Mind, Open Sight, Open Future! > > -- > 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]<google-appengine-java%[email protected]> > . > For more options, visit this group at > http://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.
