使用hibernate获取数百万条记录表的最佳方法

int pageSize = 1000; // 每页记录数
int currentPage = 1; // 当前页数

Criteria criteria = session.createCriteria(YourEntity.class);
criteria.setFirstResult((currentPage - 1) * pageSize);
criteria.setMaxResults(pageSize);

List<YourEntity> entities = criteria.list();

int batchSize = 1000; // 每批处理的记录数

Transaction transaction = session.beginTransaction();

Query query = session.createQuery("update YourEntity set column = :value");
query.setParameter("value", newValue);

int totalRecords = 1000000; // 总记录数
int totalBatches = (totalRecords + batchSize - 1) / batchSize; // 总批次数

for (int i = 0; i < totalBatches; i++) {
    query.setFirstResult(i * batchSize);
    query.setMaxResults(batchSize);
    query.executeUpdate();
    
    if (i % 100 == 0) { // 每100批提交一次事务
        session.flush();
        session.clear();
        transaction.commit();
        transaction = session.beginTransaction();
    }
}

transaction.commit();