I have a Two objects : Batch and User
The relation is many to many between them.

User can belong to many batches.
Batch can have Many Users.


now i want to add a new User to an Existing Batch.


Mapping is as follows

<hibernate-mapping package="com.model">

<class name="Batch" table="Batch" dynamic-update="true"
dynamic-insert="true" select-before-update="false" >

<id name="batchId" type="long" column="BatchId">
<generator class="native"></generator>
</id>

<set name="users" table="Batch_User" cascade="save-update"
lazy="true" >
<key>
<column name="BatchId" not-null="true" />
</key>
<many-to-many class="BatchUser" column="UserId" />
</set>

</class>
</hibernate-mapping>



Please help me to add a new User to the existing Batch without deleting the existing users in the Batch.


Thanks in Advance.

Could you show xml mapping for BatchUser class

PS:
use tag [code] to show java or xml code - just press "code" button.