原来这是一个未经审查的问题。感谢Brent Worden关于交易的问题让我环顾四周，注意到我已经禁用了自动提交，并且在查询后没有提交。

Turns out it was a matter of uncommited queries. Thanks to Brent Worden for the question about transactions which led me to look around and notice that I had disabled auto commit and was not committing after queries.

所以解决方案有效对我来说：

So the solutions that worked for me:

conn.setAutoCommit(true);

或

statement.executeQuery(query);
conn.commit();

这样可以刷新查询并防止过时数据。

This allows the queries to be flushed out and stale data is prevented.