I have two tables. Table class and table instance.

class:

templateRefId;



Instance:

instId;
templateRefId;




There is a one to many between table class and table Instance. One row in table a will have many entries in the table b.


for table Class the mapping is defined as follows :
<class name="Class" table="Class">
<id name="tempRefId" column="templateRefId" type="int" unsaved-value="0">
<generator class="increment"/>
</id>
<set name="instances" inverse="true">
<key column="templateRefId"/>
<one-to-many class="Instance"/>
</set>
</class>





class InstanceData that desribes the table b has the following mapping.
<class name="Instance" table="Instance">
<id name="instId" column="instanceId" type="int" unsaved-value="0">
<generator class="increment"/>
</id>
<property name="tempRefId" column="templateRefId" type="int" />
<!-- <many-to-one name="tempRefId" class="Class" column="templateRefId"/> -->
</class>




I want this relation to be bi-directional. Please let me know what should be changed for this to work. When i try to execute the code with the following mapping i get a SQL error saying that the FORIEGN KEY constraint has been violated. The insert into class goes fine. I am kind off stuck and documentation is not taking me anywhere.

class InstanceData that desribes the table b has the following mapping.
<class name="Instance" table="Instance">
<id name="instId" column="instanceId" type="int" unsaved-value="0">
<generator class="increment"/>
</id>
<property name="tempRefId" column="templateRefId" type="int" />
<!-- <many-to-one name="tempRefId" class="Class" column="templateRefId"/> -->
</class>

Remove the bold line and remove the comment of the underlined line, it should work. The tempRefId can't be used twice in the class, i.e. for a reference and a instance value.

This is a FAQ. See the manual - specifically Chapter 9, section 9.2: Bidirectional one to many. The problem and solution is detailed there.

Hello. Thank you very much. I did make that correction. I am a bit confused with whats happening now. The error is




net.sf.hibernate.HibernateException: SQL update or deletion failed (row not found)
net.sf.hibernate.HibernateException: SQL update or deletion failed (row not found)
at net.sf.hibernate.impl.NonBatchingBatcher.addToBatch(NonBatchingBatcher.java:25)
at net.sf.hibernate.persister.EntityPersister.update(EntityPersister.java:672)
at net.sf.hibernate.persister.EntityPersister.update(EntityPersister.java:625)
at net.sf.hibernate.impl.ScheduledUpdate.execute(ScheduledUpdate.java:52)
at net.sf.hibernate.impl.SessionImpl.executeAll(SessionImpl.java:2308)
at net.sf.hibernate.impl.SessionImpl.execute(SessionImpl.java:2262)
at net.sf.hibernate.impl.SessionImpl.flush(SessionImpl.java:2187)
at com.trulogica.truaccess.wfengpersist.dao.WfTemplateDAOTest.testSaveTemplate(Unknow
at com.trulogica.truaccess.wfengpersist.ejb.WfTemplateEJB.addTemplate(Unknown Source)
at com.trulogica.truaccess.wfengpersist.ejb.WfTemplateEJB_5hsagc_EOImpl.addTemplate(W
at com.trulogica.truaccess.wfengpersist.ejb.WfTemplateEJB_5hsagc_EOImpl_WLSkel.invoke
at weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:360)
at weblogic.rmi.cluster.ReplicaAwareServerRef.invoke(ReplicaAwareServerRef.java:93)
at weblogic.rmi.internal.BasicServerRef.handleRequest(BasicServerRef.java:329)
at weblogic.rmi.internal.BasicExecuteRequest.execute(BasicExecuteRequest.java:22)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:140)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:121)

I am not doing a update or delete. I am just trying to ininsert into the class table and then into the instance table. Why is that a update being issued. The code is given below.


Class c = new Class();
Set instances = new HashSet();
Instance instance0 = new Instance();
instances.add(instance0);
template.settempRefId(instances);
Session session = PersistenceManager.getSession();
session.saveOrUpdate(template);
session.flush();
System.out.println("call flush done");
session.connection().commit();


I read through the documentation. Somehow i am not really getting a grip on that. Please do help out.

I see that you have set your unsaved value to 0. What this this field inited to when you create the object?

Remove the unsave-value=0 value. You use a hibernate generated key. Setting the unsave-value to 0 will tell Hibernate only to save new instances of this object with key value is 0 and to update instances with another key value. Because Hibernate sets the key value to another value then 0 it will try to update the object and it will fail, giving a Row not found exception.

This also applies to unsaved-value is 0 for the Instance key in your mapping file.

Hello:

Thanks for the help. But i am still getting the same error. Its trying to update when i have to insert into the database.

Hello:

Thanks for the help. But i am still getting the same error. Its trying to update when i have to insert into the database.

Hello:

Thanks for the help. But i am still getting the same error. Its trying to update when i have to insert into the database.

This is for sure related to usaved-value, reread the doc and FAQ on that subject, it will help you a lot: this is a key feature of Hibernate

Exactly. I solved the issue by changing the unsaved-value param. But now i am getting a different error.


Caused by: java.sql.SQLException: Syntax error converting the nvarchar value 'TemplateId1' to a column of data type int.

I am trying to find a row with the following query.

String queryStr = " FROM templateId in class WfTemplateData where
templateId=? "
results = session.find(queryStr, tempId, Hibernate.STRING);



My class is defined as (i have trimmed the unwanted fields)



public class WfTemplateData {

/**
* @return
* @hibernate.property column="templateId" type="string" length="50" not-null="true"
*/

// THIS FIELD IS VARCHAR (50) IN THE MS SQL DATABASE
public String getTemplateId() {
return templateId;
}



/**
* @param string
*/
public void setTemplateId(String string) {
templateId = string;
}

}[/b]

When I look at you mapping file I see:
<id name="tempRefId" column="templateRefId" type="int" unsaved-value="0">
<generator class="increment"/>
</id>

You problably want this to be type="string".

Reading the documentation is a good starter. It's explained there. You problably also want to set the unsaved-value to null (the default) because you use an Object as indentification.

Hi.

The problem is really in the templateId field. Its not in remplateRefId field. Just prior to reply i gave you the .java files with the mappings. Please let me know.

You should check your posts. You haven't supplied the mapping of Template, only the sourcecode. We can't assume you've done the mapping correctly.

<property
name="templateId"
type="string"
update="true"
insert="true"
column="templateId"
length="50"
not-null="true"
/>