不能rollback，但可以roll forward。 这篇可能对你有帮助： http://www.keakon.net/article/1843
---------- keakon My blog(Chinese): www.keakon.net Blog source code: https://bitbucket.org/keakon/doodle/ 2010/12/16 EtuO <[email protected]> > 谢谢大家，只能开启两个事务来解决啦。 > > 在 2010年12月16日 下午6:11，kartik kudada <[email protected]>写道： > > 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]<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. > -- 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.
