Hi:
Does anyone konw how to use batch update feature in the hibernate?Please send me a example.Thanks in advance

You simply set


hibernate.jdbc.batch_size=10


or whatever

O Yes,I did so.But it did not work.

perhaps your jdbc driver does not implement batch updates (this is very common)

Thanks.My JDBC Driver is mysql mysql connector 3.08 stable.And the driver support batch mode.The following is my config file content:
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-2.0.dtd">

<hibernate-configuration>

<session-factory>
<!--hibernate jdbc configuration -->
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test?useUnicode=true&amp;characterEncoding=Big5</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password"></property>
<property name="hibernate.connection.pool_size">10</property>
<property name="hibernate.connection.password"></property>
<property name="hibernate.jdbc.batch_size">25</property>
<property name="show_sql">ture</property>
<property name="use_outer_join">true</property>
<property name="dialect">net.sf.hibernate.dialect.MySQLDialect</property>
<!--hibernate jdbc configuration end -->

<!-- Mapping files -->
<mapping resource="mapping.hbm.xml"/>
<mapping resource="child.hbm.xml"/>
</session-factory>

</hibernate-configuration>

and the test server code is :
public void createParent(Parent parent,int count) throws HibernateException {
for (int i=0;i<count;i++){
session.save(parent);
}
}

test client code is :
public void testCreateParent() throws HibernateException{
application.beginTransaction();
application.createParent(parent,10);
application.endTransaction(true);
}

but the result is just that only a result is inserted.
why?

Ummmmm.


This code would only insert one record even if batch updates are _dis_abled.

If you read the Hibernate documentation, it explains how the Hibernate session-level cache works. You can't save the same instance multiple times and have it somehow transform itself into multiple instances.

Oh,Thanks."have it somehow transform itself into multiple instances".Could you tell me in detail.

Excuse me! Is it convenient for you to post me a sample code snippet about batch save(update/delete).

Hi,

In your test code you wrote:

for (int i = 0; i < count; i++) {
session.save(parent);
}

since parent's pk field never changes in the loop, you are trying to save the same object (into the same table row) that many times, of course only one row will be saved.

Clarence

Oh,The pk is generate by uuid and it is defined in the mapping file.

just to double check...

If I want to do batch writes to the database all I have to do is set the property in the config file...

<property name="hibernate.jdbc.batch_size">25</property>

I have a few questions about how the batch stuff works.

Does Hibernate store the items you are going to insert/update in the session until it reaches it's batch limit, then write everything?

If the limit is never reached, I assume it does the batch when commit() is called, is that correct?

If I am using the "identity" id generation method and I insert a row with batch enabled, do I have the ability to get the PK from the recently inserted object, even if the batch has not gone off?

Finally, is there a limit to the batch_size or a number that you would suggest not going above?

Thanks!
Chris