The problem:

As soon as i add the many-to-one associations to my hibernate mapped User class below i get a Duplicate key or integrity constraint violation.

Basically the problem is that the user.getId property does not seem to get recognised and passed to the sql.

I have also noticed that if i search (HQL) on any field mapped via the association it never returns anything. Even if the search is valid.


Please see below...



Hibernate version: 3.2.2

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">
<hibernate-mapping package="com.jafp.objects.cms">

<class name="ContentItem" table="CMS_ContentItem">
<cache usage="read-write"/>
<id name="id" column="id" type="integer" unsaved-value="0">
<generator class="native"/>
</id>
<property name="active"/>
<property name="status"/>
<property name="title"/>
<property name="description" type="text"/>
<property name="feature"/>
<property name="releaseDate"/>
<property name="createdDate"/>
<many-to-one name="createdBy" class="com.jafp.objects.forum.User" cascade="none"/>
<property name="modifiedDate"/>
<many-to-one name="modifiedBy" class="com.jafp.objects.forum.User" cascade="none"/>

<property name="threadId"/>
<property name="imageName"/>
<property name="thumbnailName"/>
<property name="comments"/>

</class>
</hibernate-mapping>


<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.jafp.objects.forum">

<class name="User" table="vBulletin_user">
<id name="id" column="userid" type="integer" unsaved-value="0">
<generator class="native"/>
</id>
<property name="memberGroupIds" column="membergroupids"/>
<property name="userGroupId" column="usergroupid"/>
<property name="username" column="username"/>
<property name="email" column="email"/>
</class>
</hibernate-mapping>





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


User user = getHibernateTemplate().load(User.class, 1);

Company owner = new Company();

owner.setTitle(OWNERS[i]);
owner.setCreatedDate(createdDate);
owner.setCreatedBy(owner);
owner.setModifiedDate(createdDate);
owner.setModifiedBy(owner);

hibernateDao.saveOrUpdate(owner);


getHibernateTemplate().saveOrUpdate(object);



Full stack trace of any exception that occurs:


Hibernate: insert into CMS_ContentItem (active, status, title, description, feature, releaseDate, createdDate, createdBy, modifiedDate, modifiedBy, threadId, imageName, thumbnailName, comments, itemType) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
2007-03-27 23:16:22,656 WARN httpWorkerThread-8141-0 - SQL Error: 1216, SQLState: 23000
2007-03-27 23:16:22,671 ERROR httpWorkerThread-8141-0 - Duplicate key or integrity constraint violation message from server: "Cannot add or update a child row: a foreign key constraint fails"
ApplicationDispatcher[/Web] Servlet.service() for servlet jsp threw exception
org.hibernate.exception.ConstraintViolationException: could not insert: [com.jafp.objects.cms.Company]
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:71)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:40)



Name and version of the database you are using:

MySql 4.1.22

One problem is using the Hibernate template :-)

Apart from that, what is your hibernateDao doing?
Maybe this is not really al that is happening between open and close of the session (Doesn't spring's HibernateTemplate open/close a session if no transaction is active? I didn't bother to check the Spring sources, it doesn't say if it does/doesn't in the API docs.)
Also, you call setModifiedBy with the company instance (not the user). This cannot be the real code right?

Also, your hashCode and equals might be wrong.

Yes your correct that was dummy code.

Ok i've got to the bottom of this but am unsure what to do to solve it:


The problem is:

1) Schema export is putting a foreign key constraint on the createdBy and modifiedBy columns.

2) I then drop the vbulletin_user table and create it according to vbulletin forum software (this breaks the constraint)

3) When i execute even a native sql insert on the cms_contentitem table it will fail. Even if the correct createdBy value is set.



The question therefore is.... Is their a way to prevent Schema export adding a constraint for this foreign key??