one to many persist question

angeldude · **Posted:** Fri Jan 30, 2009 7:05 am

Hi All,

I have a classic one to many persist problem. Bellow are my entities:

Parent class
========

@Id
@GeneratedValue(strategy = SEQUENCE, generator = "seq_idP")
private long idP;

@OneToMany(mappedBy = "idPChildren", cascade = { CascadeType.ALL }, fetch = EAGER)
private List<Children> childrenCollection;

Children class
=========

@EmbeddedId
private ChildrenPK pk;

@ManyToOne
@JoinColumn(name = "idP", referencedColumnName = "idP", insertable = false, updatable = false)
private Children idPChildren;

PK Class
======

@Column(name = "idP", insertable = false, updatable = false)
private long idP2;
private long line;

We take above example and map it to Invoice-InvoiceLines one-to-many mapping.

What are the problems?
1. if I have
1 Invoice with say 1 InvoiceLines
and I edit this, adding another InvoiceLines I'd have:

1 Invoice with 2 InvoiceLines
In my application I use em.merge to save this in the database, however only 1 InvoiceLines object is updated and the 2nd line is not added.

My understanding of "merge" is that it should update what already exists and add what's new. Am I correct?

2.

if I create a completely new object Invoice and add two new lines of InvoiceLines object then I try to "persist" them I get the error:

13:02:07,406 ERROR [JDBCExceptionReporter] ERROR: insert or update on table "InvoiceLines" violates foreign key constraint "fkInvoiceInvoicelines"
Detail: Key (idinvoice)=(0) is not present in table "Invoice".

this makes me think that during the persist first is getting inserted the children rows and then the primary, because otherwise the Parent primary key would get generated as its a sequence.

Is there another approach to solve this?

Thank you for your help.

mike1106 · **Joined:** Mon Oct 04, 2004 7:13 am **Posts:** 19

remove the insertable/updatable=false

mike1106 · **Joined:** Mon Oct 04, 2004 7:13 am **Posts:** 19

remove all the insertable/updatable=false

angeldude · **Posted:** Fri Jan 30, 2009 12:29 pm

if I remove both, I get:

Code:

javax.persistence.PersistenceException: org.hibernate.MappingException: Repeated column in mapping for entity: InvoiceLines column: idP (should be mapped with insert="false" update="false")

that's because the primary key is referenced both in the PK class and Children class.

angeldude · **Posted:** Mon Feb 02, 2009 12:27 pm

hi guys,

don't want to sound too pushy but I don't think I'm the only who got into this problem. Well, if I am I guess this is a bug. Any help is very much appreciated.

thanks

mmerder · **Posted:** Mon Feb 02, 2009 12:35 pm

Change your mapping as followed:

Code:

Parent class
========

@Id
@GeneratedValue(strategy = SEQUENCE, generator = "seq_idP")
private long idP;

@OneToMany(mappedBy = "pk.idPChildren", cascade = { CascadeType.ALL }, fetch = EAGER)
private List<Children> childrenCollection; 

Children class
=========

@EmbeddedId
private ChildrenPK pk;


PK Class
======

@ManyToOne
@JoinColumn(name = "idP", referencedColumnName = "idP")
private Parent idPChildren;
private long line; 

Alternatively you could use @IdClass instead of @EmbeddedId, if you don't want to navigate across "pk" to get a Parent.

angeldude · **Posted:** Tue Feb 03, 2009 11:23 am

this solved my problem, thanks :-)

angeldude · **Posted:** Wed Feb 04, 2009 10:42 am

Sorry to reopen this thread,

I've played around with the solution. It works well with em.persist but it produces a java.lang.StackOverflowError for em.merge.

Please find below a snippet of the stack trace:

Code:

16:32:56,796 DEBUG SocketWrapper:123 - ClientSocketWrapper[Socket[addr=/127.0.0.1,port=3873,localport=2822].107ebe1] closing
javax.ejb.EJBException: java.lang.RuntimeException: java.lang.StackOverflowError
   at org.jboss.ejb3.tx.Ejb3TxPolicy.handleExceptionInOurTx(Ejb3TxPolicy.java:63)
   at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:83)
   at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:191)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
   at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
   at org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
   at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77)
   at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:110)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
   at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
   at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
   at org.jboss.ejb3.stateless.StatelessContainer.dynamicInvoke(StatelessContainer.java:304)
   at org.jboss.aop.Dispatcher.invoke(Dispatcher.java:106)
   at org.jboss.aspects.remoting.AOPRemotingInvocationHandler.invoke(AOPRemotingInvocationHandler.java:82)
   at org.jboss.remoting.ServerInvoker.invoke(ServerInvoker.java:769)
   at org.jboss.remoting.transport.socket.ServerThread.processInvocation(ServerThread.java:573)
   at org.jboss.remoting.transport.socket.ServerThread.dorun(ServerThread.java:373)
   at org.jboss.remoting.transport.socket.ServerThread.run(ServerThread.java:166)

I'm not really sure what's the problem.

[/code]

Right now the mappings are:

Code:

Parent class
========

@Id
@GeneratedValue(strategy = SEQUENCE, generator = "seq_idP")
private long idP;

@OneToMany(mappedBy = "pk.idPChildren", cascade = { CascadeType.ALL }, fetch = EAGER)
private List<Children> childrenCollection;

Children class
=========

@EmbeddedId
private ChildrenPK pk;


PK Class
======

@ManyToOne
@JoinColumn(name = "idP", referencedColumnName = "idP")
private Parent idPChildren;
private long line; 

I've looked trough some of the posts in this forum but couldn't find any to match my problem.

Thanks for all your help

angeldude · **Posted:** Thu Feb 05, 2009 10:47 am

Guys

Managed to find the solution. It seems that this is a bug in Hibernate.

Take a look at this:

http://opensource.atlassian.com/project ... se/EJB-225

WORKAROUND
==========

In primary key class set:
@ManyToOne(fetch = LAZY)

By default (fetch = EAGER) for the Primary Key class. If you have fetch=EAGER in the @OneToMany entity as well then StackOverflowError is produced.

Thanks