HIbernate"StaleStateExcema：批处理更新从更新[0]返回意外的行计数；实际行计数：0；预期：1"

Question

当现有用户发出请求时，该方法首先删除最旧的记录，然后再保存新请求。如果请求传入的速度不太快（使用Oracle数据库），下面的代码可以正常工作。

   public Request saveRequest(Request req)
   {
      String user = req.getUser();
      
      // Do a NamedQuery on the entity to pull all requests for user
      List<Request> requestList = getRequests(user);
      
      LOGGER.info("Request List size is " + requestList.size() + " for " + user);
      
      // Sort the list then delete the first/oldest request
      Comparator<Request> bySessionDate = Comparator.comparing(Request::getDate);
      Collections.sort(requestList, bySessionDate);
         
      LOGGER.info("Deleting request id " + requestList.get(0).getId());

      deleteById(requestList.get(0).getId());

      Request sreq = requestRepository.create(req);
      LOGGER.info("Saved request for user " + sreq.getUserId());
      return sreq;
   }

输出：

2021-01-20 00:39:12,167 INFO  [beez.service.RequestManager] (default task-4) Request List size is 250 for Bob
2021-01-20 00:39:12,168 INFO  [beez.service.RequestManager] (default task-4) Deleting request id 757A9B21E51D49199F2E182F68BC6BF7
2021-01-20 00:39:12,171 INFO  [beez.service.RequestManager] (default task-4) Deleted: 757A9B21E51D49199F2E182F68BC6BF7
2021-01-20 00:39:12,173 INFO  [beez.service.RequestManager] (default task-4) Saved request for user Bob
2021-01-20 00:39:15,375 INFO  [beez.service.RequestManager] (default task-3) Request List size is 250 for Bob
2021-01-20 00:39:15,375 INFO  [beez.service.RequestManager] (default task-3) Deleting request id 27239B85472C45EDA5495E98523295F3
2021-01-20 00:39:15,377 INFO  [beez.service.RequestManager] (default task-3) Deleted: 27239B85472C45EDA5495E98523295F3
2021-01-20 00:39:15,380 INFO  [beez.service.RequestManager] (default task-3) Saved request for user Bob

但是，如果用户以非常快速的方式提交请求，即happy clicker，则相同的代码会生成StaleStateException错误。

2021-01-20 00:42:31,307 INFO  [beez.service.RequestManager] (default task-3) Request List size is 250 for Bob
2021-01-20 00:42:31,307 INFO  [beez.service.RequestManager] (default task-3) Deleting request id 55E43DF4D83E4BF5AD73DE47A49B0DA9
2021-01-20 00:42:31,310 INFO  [beez.service.RequestManager] (default task-3) Deleted: 55E43DF4D83E4BF5AD73DE47A49B0DA9
2021-01-20 00:42:31,313 INFO  [beez.service.RequestManager] (default task-3) Saved request for user Bob
2021-01-20 00:42:31,332 INFO  [beez.service.RequestManager] (default task-7) Request List size is 250 for Bob
2021-01-20 00:42:31,332 INFO  [beez.service.RequestManager] (default task-7) Deleting request id 55E43DF4D83E4BF5AD73DE47A49B0DA9
2021-01-20 00:42:31,492 ERROR [org.jboss.as.ejb3.invocation] (default task-7) WFLYEJB0034: EJB Invocation failed on component RequestManager for method public beez.entity.RequestManager service.RequestManager.saveRequest(beez.entity.RequestManager): javax.ejb.EJBTransactionRolledbackException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
.
.
.
Caused by: org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1

似乎在下一条记录出现之前，代码还没有时间完成更改，导致代码尝试删除同一条记录两次。除了在这种方法之前改变前端或其他东西，还有什么方法可以解决这个问题吗？

我尝试了@Transactional和@Lock选项，但没有成功。在该线程中花费了大量时间，但解决方案要么不起作用，要么不适用：Hibernate-批量更新从更新中返回了意外的行数：0实际行数：0预期：1

Answer 1

如果用户不希望快速点击，强烈建议您考虑在前面取消对API请求的公告，以跳过背靠背的请求/事件。

正如您所说的，由于加载到单个会话中的实体与数据库的当前状态不一致，问题正在发生。

这可以通过多种方式解决，比如使用悲观锁定（选择更新）带来的性能瓶颈，同步方法。。。。等

最简单的处理方法是使用JPA查询进行删除，并在数据库级别进行排序，因此这始终适用于记录表的当前状态。

delete from request where id= (select req.id from request req left join user usr on usr.id = req.userId where usr.userId=? order by req.date LIMIT 1)

请根据您的实体设计更正以上查询。