I have modelled a question object with one to many relationship with Answer objects.

I have used cascade="all-delete-orphan" to ensure that whenever the parent (Quesiton) is deleted , all the associated Children (Answer)should be deleted. For some reason the children are not deleted. Can you please take a look at it?

Hibernate version:3

Mapping documents:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Apr 18, 2008 11:13:26 AM by Hibernate Tools 3.2.1.GA -->
<hibernate-mapping>
<class name="com.survey.model.SurveyQuestion" table="SurveyQuestion" >
<id name="questionId" type="big_decimal">
<column name="QUESTION_ID" precision="22" scale="0" />
<generator class="assigned" />
</id>
<many-to-one name="SurveyQuestionTypes" class="com.survey.SurveyQuestionTypes" fetch="select">
<column name="QUESTION_TYPE" length="20" />
</many-to-one>
<property name="status" type="string">
<column name="STATUS" length="20" />
</property>
<property name="text" type="string">
<column name="TEXT" length="1000" />
</property>
<property name="createdBy" type="string">
<column name="CREATED_BY" length="20" />
</property>
<property name="creationDate" type="timestamp">
<column name="CREATION_DATE" length="11" />
</property>
<property name="lastUpdatedBy" type="string">
<column name="LAST_UPDATED_BY" length="20" />
</property>
<property name="lastUpdatedDate" type="timestamp">
<column name="LAST_UPDATED_DATE" length="11" />
</property>
<property name="altText" type="string">
<column name="ALT_TEXT" length="1000" />
</property>
<set name="surveyAnswers" inverse="true" cascade="all,delete-orphan">
<key>
<column name="QUESTION_ID" precision="22" scale="0" />
</key>
<one-to-many class="com.survey.model.SurveyAnswer" />
</set>
<set name="surveyQuestionSets" inverse="true" cascade="all,delete-orphan">
<key>
<column name="QUESTION_ID" precision="22" scale="0" />
</key>
<one-to-many class="com.survey.model.SurveyQuestionSet" />
</set>
</class>
</hibernate-mapping>



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

Session session = null;
try{
session = this.sessionFactory.getCurrentSession();
Transaction txn=session.beginTransaction();

//delete the question
SurveyQuestionDao surveyQuestionDao = new surveyQuestionDao ;
surveyQuestionDao.deleteQuestion(question,session);

txn.commit();
// return result;
return 1;
}catch(Exception e)

Full stack trace of any exception that occurs:

Name and version of the database you are using:
oracle 9i

The generated SQL (show_sql=true):
delete from SURVEY_QUESTION where question_id=?

Debug level Hibernate log excerpt:


Problems with Session and transaction handling?

Read this: http://hibernate.org/42.html

What is inside deleteQuestion?


Farzad-

I think that you are supposed to first attach your question object to the session, if you want any changes to its children to take effect during commit. correct? Otherwise, you have to call session.save() or merge(), depending on what you're trying to achieve...

This is the namedquery I am using inside deleteQuestion

delete from SurveyQuestion question where question.questionId=:questionId

Thanks for your time.

did you make sure that your DDL is generated with ON DELETE CASCADE for the foreign key between answer and question? AFAIK, bulk-delete will only work as expected if the DDL has this declared.

The DDL reads as ON DELETE SET NULL which exactly is happening. It is a legacy database and I cannot change that.

Will the database cascade instruction takes priority over the hibernate specification?

Thanks for your time.

Not exactly. When hibernate generates an SQL query that relies on database cascading, the db cascading will be used. Sometimes, hibernate does not utilize db cascading, i.e. it manually generates multiple 'delete' queries in the correct order, to delete a certain entity and its dependencies. However, this is usually not supported for bulk-operations. Try this: instead of deleting using a bulk-operation, use the hibernate session delete/remove method and see if it makes any difference for a single entity.