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如果表内容更改，是否更新RowSet？

[英]Updating RowSet if table content is changed?

原文 2010-02-15 19:43:52 5 2 java/ jdbc/ cachedrowset/ rowset

Is it possible to update/refresh a RowSet 's in case the table content is changed (for eg another application modifies it)? 如果表内容被更改（例如，另一个应用程序对其进行了修改），是否可以更新/刷新RowSet ？ So this way I 'always' have an up-to-date version of the table. 因此，通过这种方式，我“始终”拥有该表的最新版本。

I looked into RowSetListener , but these events seem to get invoked only if I make modifications to the RowSet directly. 我查看了RowSetListener ，但是只有直接修改RowSet才似乎会调用这些事件。 It would be enough to know that there was a change, I know... that's a lot :) 知道发生了变化就足够了，我知道...很多。:)

Please share your thoughts! 请分享您的想法！ Thanks in advance! 提前致谢！ Daniel 丹尼尔

2 个解决方案

No, there are no any way, for most traditional RDBMS. 不，对于大多数传统的RDBMS，没有任何办法。 Just because of http://en.wikipedia.org/wiki/ACID#Isolation 只是因为http://en.wikipedia.org/wiki/ACID#Isolation

Yes, a RowSet can be refreshed. 是的，可以刷新RowSet。 Just call its "execute()" method again. 只需再次调用其“ execute（）”方法即可。

Per the docs : 根据文档：

If this method is successful, the current contents of the rowset are discarded and the rowset's metadata is also (re)set. 如果此方法成功，则将丢弃行集的当前内容，并且还将（重新）设置行集的元数据。

A rowSetChanged event fires upon this refresh. 刷新时将触发rowSetChanged事件。

If you are asking if a RowSet can be automatically refreshed when data is changed on the database server: No way that I know of. 如果您要问在数据库服务器上更改数据时RowSet是否可以自动刷新：我不知道。 You may not want to know of such changes, depending on your isolation level, locking, and MVCC strategy. 您可能不希望知道这些更改，具体取决于您的隔离级别，锁定和MVCC策略。