I'm, trying to implement cascade saving in the posted code below.

I'm trying to reproduce the examples provided in section 16.3 in Hibernate reference documentation (2.1.7).

I get

net.sf.hibernate.HibernateException: Batch update row count wrong: 0

while trying...


Hibernate version:
2.1.7c
Mapping documents:

<class name="Parent" table="Parent">
<id name="id" column="id">
<generator class="native" />
</id>

<property name="name" />

<set name="children" inverse="true" cascade="all">
<key column="parent_id" />
<one-to-many class="Child" />
</set>

</class>

<class name="Child" table="Child">
<id name="id" column="id">
<generator class="native" />
</id>

<many-to-one name="parent" class="Parent" column="parent_id" not-null="true"/>

<property name="name" />
</class>


Code between sessionFactory.openSession() and session.close():


Full stack trace of any exception that occurs:

net.sf.hibernate.HibernateException: Batch update row count wrong: 0

Name and version of the database you are using:
Mysql 4.1.12 Win

The generated SQL (show_sql=true):

Hibernate: select parent0_.id as id0_, parent0_.name as name0_ from Parent parent0_ where parent0_.id=?
- PREPARE created: Tue Aug 16 13:21:20 EEST 2005 duration: 15 connection: 0 statement: 3 resultset: -1 message: select parent0_.id as id0_, parent0_.name as name0_ from Parent parent0_ where parent0_.id=?
- EXECUTE created: Tue Aug 16 13:21:20 EEST 2005 duration: 0 connection: 0 statement: 3 resultset: -1
Hibernate: select children0_.parent_id as parent_id__, children0_.id as id__, children0_.id as id0_, children0_.parent_id as parent_id0_, children0_.name as name0_ from Child children0_ where children0_.parent_id=?
- PREPARE created: Tue Aug 16 13:21:20 EEST 2005 duration: 0 connection: 0 statement: 4 resultset: -1 message: select children0_.parent_id as parent_id__, children0_.id as id__, children0_.id as id0_, children0_.parent_id as parent_id0_, children0_.name as name0_ from Child children0_ where children0_.parent_id=?
- EXECUTE created: Tue Aug 16 13:21:20 EEST 2005 duration: 0 connection: 0 statement: 4 resultset: -1
Hibernate: update Child set parent_id=?, name=? where id=?
- PREPARE created: Tue Aug 16 13:21:20 EEST 2005 duration: 0 connection: 0 statement: 5 resultset: -1 message: update Child set parent_id=?, name=? where id=?
- EXECUTE created: Tue Aug 16 13:21:20 EEST 2005 duration: 0 connection: 0 statement: 5 resultset: -1
- Could not synchronize database state with session
- QUERY created: Tue Aug 16 13:21:20 EEST 2005 duration: 0 connection: 0 statement: 999 resultset: 0 message: rollback
- FETCH created: Tue Aug 16 13:21:20 EEST 2005 duration: 0 connection: 0 statement: 999 resultset: 0

Debug level Hibernate log excerpt:

A few points in no particular order, may or may not help:

I notice that in your mapping file, you define children as having a required parent, but I don't ever see where you call child.setParent(parent);

Try changing the inverse="true" in the parent to inverse="false" and see if that makes any difference

I think the most striking thing is that there is no INSERT statement anywhere in the generated SQL - if you figure that out, you'll probably have your solution.

Hi and thank your for your reply. I tried to follow the example code provided in section 16.3. Apparently I am missing something. First I thought the example was in some way Hibernate 3:ish but at least the guide says 2.1.7.

I recall I have been trying the very same example before without success.

Oh, the method addChild() in class Parent adds the Parent object to the Child object (copied from the example).