Reusing a PreparedStatement for Multiple Operations
In scenarios where a single connection is utilized without a connection pool, there's a question regarding the approach to creating and using PreparedStatements. One option is to create a new PreparedStatement instance for each SQL/DML operation:
<code class="java">for (int i=0; i<1000; i++) { PreparedStatement preparedStatement = connection.prepareStatement(sql); preparedStatement.setObject(1, someValue); preparedStatement.executeQuery(); preparedStatement.close(); }
Alternatively, the same PreparedStatement instance can be reused by clearing its parameters and re-setting values:
<code class="java">PreparedStatement preparedStatement = connection.prepareStatement(sql); for (int i=0; i<1000; i++) { preparedStatement.clearParameters(); preparedStatement.setObject(1, someValue); preparedStatement.executeQuery(); } preparedStatement.close();
Recommendation and Multithreaded Considerations
For optimal efficiency, consider executing PreparedStatement operations in batches:
<code class="java">public void executeBatch(List<Entity> entities) throws SQLException { try ( Connection connection = dataSource.getConnection(); PreparedStatement statement = connection.prepareStatement(SQL); ) { for (Entity entity : entities) { statement.setObject(1, entity.getSomeProperty()); // ... statement.addBatch(); } statement.executeBatch(); } }</code>
When working with multithreaded environments, it's crucial to acquire and close connections and statements within the shortest possible scope within the same method block. Following the JDBC idiom using try-with-resources ensures resource management is handled appropriately.
For transactional batches, disable autocommit on the connection and commit only after all batches have completed successfully to avoid potential database inconsistencies.
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