在executeBatch（）之后使用CallableStatement检索ResultSet [英] Retrieve ResultSet using CallableStatement after executeBatch()

问题描述

我需要多次调用存储过程并为此使用 executeBatch（）。每次调用都应返回包含结果的表，但我无法访问此结果。下一个代码工作正常：

I need to call stored procedure multiple times and use executeBatch() for this. Every call should return table with results, but I could not access this results. Next code works fine:

callableStatement.setString(1, "foo");
callableStatement.setString(2, "bar");
callableStatement.execute();
resultSet = callableStatement.getResultSet();

但是下一个代码没有按预期工作：

But next code doesn't work as expected:

for (String str : strings) {
    callableStatement.setString(1, str);
    callableStatement.setString(2, "bar");
    callableStatement.addBatch();
}
callableStatement.executeBatch();
resultSet = callableStatement.getResultSet(); // returns null

我已经尝试调用 callableStatement.getUpdateCount（ ）和 callableStatement.getMoreResults（）在提取ResultSet之前，但没有成功。

I've already tried to call callableStatement.getUpdateCount() and callableStatement.getMoreResults() before extracting ResultSet, but unsuccessfully.

推荐答案

这不是正确使用 #executeBatch 。批处理方法用于执行数据操作，而不是获取结果数据。也就是说，您可以执行批量插入/更新/删除但不能读取。 #executeBatch 的结果是更新计数，表示每次批处理操作进行了多少更改

This isn't really the correct use of #executeBatch. The batch methods are for doing data manipulation rather that obtaining result data. That is, you can do batch inserts/ updates/ deletes but not reads. The result of #executeBatch is the update-count, indicating how many changes were made per batched operation

意图是的，您可以通过减少网络开销和数据库往返来提高性能，以实现类似的数据操作操作。

The intention is that you can improve performance by alleviating network overhead and database round-trip for alike data manipulation operations.

您通常不会批量执行查询，因为会产生不同的查询在不同形状的 ResultSet 中（除非它们都是针对具有相同列但具有不同查询的同一个表[但为什么不只是修改您的查询]）。

You don't typically execute queries on batch because different queries would result in different shaped ResultSets (unless they were all for the same table with the same columns but a different query [but then why not just modify your query]).

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