Non-cascaded delete not working as expected.

Sharebear · **Posted:** Mon Aug 29, 2005 9:58 am

Hibernate version: 3.0.5 Annotations V 3.0 beta 2

Mapping documents:
SalesPerson.java

Code:

@Entity
public class SalesPerson {
   
   public String getEmail() {
      return email;
   }

   @Id( generate=GeneratorType.AUTO )
   public Long getId() {
      return id;
   }

         public String getName() {
      return name;
   }

   @OneToMany(
         cascade={CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REFRESH},
         fetch=FetchType.EAGER,
         mappedBy="responsible"
   )
   public Set<Market> getResponsibleMarkets() {
      return responsibleMarkets;
   }

   @Version
   public Integer getVersion() {
      return version;
   }
}

Market.java

Code:

@Entity
public class Market {
   @Id( generate=GeneratorType.AUTO )
   public Long getId() {
      return id;
   }

   public String getName() {
      return name;
   }

   @ManyToOne(
         cascade={CascadeType.ALL}
   )
   public SalesPerson getResponsible() {
      return responsible;
   }

   @Version
   public Integer getVersion() {
      return version;
   }
}

Name and version of the database you are using: MySQL 4.1.13a Connector version 3.1.10
Using MySQLInnoDBDialect

When I delete a SalesPerson that is associated to a Market I expect that the reference within the Market instance be set to null(Note I have not set CascadeType.DELETE) as a Market should still be allowed to exist. However I'm receiving a ConstraintViolationException.

Do I need to manually nullify this reference?

If so what is the most efficient method of doing this?

If not, what have I got wrong in the configuration?

Or is this a bug?

Thanks in advance for your help.

Jon

emmanuel · **Posted:** Mon Aug 29, 2005 11:32 am

You have to nullify the other side, exacly as if you were working on a Java only environment. In a plain object model, you remove the object from the collection and nullify the association on the other side.

The faste I can see is market.setResponsible(null);

The convinient way is to create some helper method on sales representative.

addMarket()
removeMarket() that does the nullify and the collection removal job.

Sharebear · **Posted:** Mon Aug 29, 2005 12:50 pm

Ok...before I saw your response, I managed to get the effect I wanted by using the following in my SalesPersonDao

Code:

public void removeSalesperson(SalesPerson person) {
   Set<Market> markets = person.getResponsibleMarkets();
   for (Market market : markets) {
      market.setResponsible( null );
      getHibernateTemplate().saveOrUpdate( market );
   }
   getHibernateTemplate().delete( person );
}

(Yes, I'm using Spring too but that shouldn't be a factor in this)

Now my new question is why doesn't the following work...

Code:

public void removeSalesperson(SalesPerson person) {
   Set<Market> markets = person.getResponsibleMarkets();
   for (Market market : markets) {
      market.setResponsible( null );
   }
   getHibernateTemplate().saveOrUpdate( person );
   getHibernateTemplate().delete( person );
}

Surely the saveOrUpdate should cascade the changes to the Market objects before I then call delete, but this doesn't happen, I again have problems with integrity constraints. At the end of the day this isn't too big a deal for me at the mo but surely the loop should be moved into a helper method within the SalesPerson class, but this is not possible as the domain object shouldn't have to know about hibernate... Ideally I would like to be able to re-write my DAO so that it becomes...

Code:

public void removeSalesperson(SalesPerson person) {
   person.removeResponsibilities();
   getHibernateTemplate().saveOrUpdate( person );
   getHibernateTemplate().delete( person );
}

Any thoughts on how this could be achieved?

Thanks

Jon

emmanuel · **Posted:** Tue Aug 30, 2005 1:33 pm

try to flush before delete

Sharebear · **Posted:** Wed Aug 31, 2005 7:36 am

Thanks for your response, I changed my code to....

Code:

public void removeSalesperson(SalesPerson person) {
   Set<Market> markets = person.getResponsibleMarkets();
   for (Market market : markets) {
      market.setResponsible( null );
   }
   markets.clear();
   getHibernateTemplate().saveOrUpdate( person );
   getHibernateTemplate().flush();
   getHibernateTemplate().delete( person );
}

I tried it with and without the markets.clear() line, but I still get the same ConstraintViolationException :-(

Any other ideas?

Jon

emmanuel · **Posted:** Thu Sep 01, 2005 7:06 pm

you update market by nullifying the relation but you don't reattach market to your session. So this update is not seen by hibernate

Sharebear · **Posted:** Fri Sep 02, 2005 9:22 am

Ok, I understand that, but if I am to avoid an Anaemic Domain Model I should be moving the loop into a method such as "removeResponsibilities" in here I would not have (and should not have) any reference to the persistence framework, so how should I go about re-attaching the Markets? Surely this is a not a new problem, people have surely manipulated one to many links before in this manner, what is the recommended practice (other than an Anaemic Domain Model)?

Thanks

Jon

emmanuel · **Posted:** Fri Sep 02, 2005 10:44 am

attach them before your loop either explicitly or through a cascade strategy

Sharebear · **Posted:** Fri Sep 02, 2005 12:01 pm

How do I do this? Due to my annotations every action other than a delete should be cascaded so I have tried the following before my loop;

Code:

getHibernateTemplate().refresh( person )

This one gives me a StackOverflowError, infinite loop maybe?...

Quote:

java.lang.StackOverflowError
at java.util.HashMap.hash(Unknown Source)
at java.util.HashMap.get(Unknown Source)
at org.hibernate.impl.SessionFactoryImpl.getCollectionPersister(SessionFactoryImpl.java:575)
at org.hibernate.engine.Cascades.cascadeAssociation(Cascades.java:786)
at org.hibernate.engine.Cascades.cascade(Cascades.java:720)
at org.hibernate.engine.Cascades.cascade(Cascades.java:847)
at org.hibernate.engine.Cascades.cascade(Cascades.java:819)
at org.hibernate.event.def.DefaultRefreshEventListener.onRefresh(DefaultRefreshEventListener.java:85)
at org.hibernate.impl.SessionImpl.refresh(SessionImpl.java:679)
at org.hibernate.engine.Cascades$3.cascade(Cascades.java:112)
at org.hibernate.engine.Cascades.cascadeAssociation(Cascades.java:771)
at org.hibernate.engine.Cascades.cascade(Cascades.java:720)
at org.hibernate.engine.Cascades.cascade(Cascades.java:847)
at org.hibernate.engine.Cascades.cascade(Cascades.java:819)
... goes on a few more times

Code:

getHibernateTemplate().merge( person )

This one gets really confusing...

Quote:

org.springframework.orm.hibernate3.HibernateOptimisticLockingFailureException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [model.SalesPerson#112]; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [model.SalesPerson#112]
org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [com.opera.interview.model.SalesPerson#112]
at org.hibernate.persister.entity.BasicEntityPersister.check(BasicEntityPersister.java:1441)
at org.hibernate.persister.entity.BasicEntityPersister.update(BasicEntityPersister.java:1986)
at org.hibernate.persister.entity.BasicEntityPersister.updateOrInsert(BasicEntityPersister.java:1909)
at org.hibernate.persister.entity.BasicEntityPersister.update(BasicEntityPersister.java:2149)
at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:75)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:239)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:223)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:137)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:274)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:730)
at org.springframework.orm.hibernate3.HibernateAccessor.flushIfNecessary(HibernateAccessor.java:394)
at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:316)
at org.springframework.orm.hibernate3.HibernateTemplate.saveOrUpdate(HibernateTemplate.java:627)
at persistence.SalesPersonDaoHibernate.removeSalesperson(SalesPersonDaoHibernate.java:58)

Code:

getHibernateTemplate().persist( person )

This one really has me stumped as I have an assertNotNull( person ) in my test case just before calling this method...

Quote:

org.springframework.dao.InvalidDataAccessApiUsageException: detached entity passed to persist: null; nested exception is org.hibernate.PersistentObjectException: detached entity passed to persist: null
org.hibernate.PersistentObjectException: detached entity passed to persist: null
at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:79)
at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:38)
at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:525)
at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:529)
at org.springframework.orm.hibernate3.HibernateTemplate$21.doInHibernate(HibernateTemplate.java:662)
at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:315)
at org.springframework.orm.hibernate3.HibernateTemplate.persist(HibernateTemplate.java:659)
at persistence.SalesPersonDaoHibernate.removeSalespersonWorking(SalesPersonDaoHibernate.java:46)

Code:

getHibernateTemplate().saveOrUpdate( person )

This gives the original ConstraintViolationException :-(

I'm obviously doing something seriously wrong here...any further ideas?

Thanks for your help so far.

Jon