Java 如何使用休眠将多行插入数据库？
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How to insert multiple rows into database using hibernate?
提问by user2848031
I'm looping list and inserting into database , but its getting updating records one by one.finally i'm seeing in database last record of the list only.
我正在循环列表并插入到数据库中，但它正在一个一个地更新记录。最后，我只在数据库中看到了列表的最后一条记录。
input name : Linux,windows,mac
输入名称：Linux,windows,mac
Session session = (Session) HibernateUtil.getSessionFactory().openSession();
String[] items = pi.getNewLicenseName().split(",");
for (String item : items)
{
feature.setName(item);
session.save(feature);
}
session.getTransaction().commit();
HibernateUtil.shutdown();
hibernate.cfg.xml:
hibernate.cfg.xml：
<hibernate-configuration>
<session-factory>
<property name="connection.driver_class">com.microsoft.sqlserver.jdbc.SQLServerDriver</property>
<property name="connection.url">jdbc:sqlserver://******</property>
<property name="connection.username">*****</property>
<property name="connection.password">*****</property>
<property name="dialect">org.hibernate.dialect.SQLServerDialect</property>
<property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>
<property name="hibernate.current_session_context_class">thread</property>
<property name="hibernate.current_session_context_class">org.hibernate.context.internal.ThreadLocalSessionContext</property>
<property name="show_sql">true</property>
<property name="hibernate.hbm2ddl.auto">update</property>
<!-- Names the annotated entity class -->
<mapping class="com.DAO.Feature"/>
</session-factory>
Here three times get the loop and inserting into database.But somehow overwriting the values.Because i'm see the sql insert and update running in console.
这里 3 次得到循环并插入到数据库中。但是以某种方式覆盖了值。因为我看到 sql 插入和更新在控制台中运行。
Hibernate: insert into FEATURE (NAME) values (?)
Hibernate: update FEATURE set NAME=? where FEATURE_ID=?
Please help me to insert the multiple rows into database.
请帮我将多行插入数据库。
采纳答案by Marcel St?r
There's a very nice chapter about batch processing in the Hibernate docs.
在 Hibernate docs 中有一个关于批处理的非常好的章节。
Set the property
设置属性
hibernate.jdbc.batch_size 20
Then use this code
然后使用此代码
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
for ( int i=0; i<100000; i++ ) {
Customer customer = new Customer(.....);
session.save(customer);
if ( i % 20 == 0 ) { //20, same as the JDBC batch size
//flush a batch of inserts and release memory:
session.flush();
session.clear();
}
}
tx.commit();
session.close();
Make sure you consider the implications for your id-generation strategy e.g. discussed here.
确保您考虑对您的 id-generation 策略的影响，例如这里讨论的。
Update 2015-09-23
更新 2015-09-23
I finally found the time to sit down and write a detailed article at https://frightanic.com/software-development/jpa-batch-inserts/.
我终于有时间坐下来在https://frightanic.com/software-development/jpa-batch-inserts/写一篇详细的文章。
回答by Arie van Wijngaarden
With the save()method in a session, Hibernate couples the object to a row and this relation remains while the session remains active. Therefore, if you use the same object, you actually update the existing row. The solution is to construct a new object for every row. In this case:
使用save()会话中的方法，Hibernate 将对象耦合到一行，并且在会话保持活动状态时这种关系仍然存在。因此，如果您使用相同的对象，实际上是在更新现有行。解决方案是为每一行构造一个新对象。在这种情况下：
for (String item : items)
{
Feature feature = new Feature();
feature.setName(item);
session.save(feature);
}
回答by samir vora
session.merge(object);
session.flush();
session.clear();
