I am relatively new to Hibernate so I have been trying a VERY simple test, running on Tomcat 5.5.

I have a 'project' table in MS SQL Server 2005 which has a project_id primary key. This is an identity column. Other tables reference this column as a foreign key.

I created a ProjectBean class which contains this relevant code:



The relevant part of my ProjectBean.hbm.xml file looks like this:



I have a simple jsp page which contains this scriptlet code:




When I run this code I get the following error:



I have tried everything I can think of to fix this. I changed the id variable from a long to a Long. In that case, my error simply stated that the value was altered from a 1 to null. I changed the generator from identity to native, with the same error. I made the project_id column in the table no longer an identity column, but then I got an error that a value was missing on the insert. I also tried to remove the primary-key/foreign key relationship between the project table and the other tables. No change. I used session.save() instead of session.saveOrUpdate(). No change.

If I reload the jsp page, the error changes by incrementing the value altered (from 2 to 0, from 3 to 0, etc.). If I change the default value of id in ProejctBean from 0 to another value (say, -1), then on the insert the instance gets altered instead to the new value (-1), not 0:



I have seen A LOT of posts on this forum and throughout the web where people encountered a similar issue but I have not seen any good responses. Indeed, there has been no response to most of the posts in this forum on the matter.

Can someone please give me a definitive cause for this problem. I can't imagine an example that is more simple than this, so if it does not work, there must be a simple way to fix it.

Thanks.[/code]

When you have in your jsp, one of these methods is not project.setId(), is it? Also, for SQL Server, generator=native and generator=identity is equivalent. Also, try explicitly setting the unsaved-value=0 in the <id> element.

i just used project.setXXX() to denote that properties were being set. I do not call setId() explicitly.

I added in unsaved-value="0", but that did not make a difference.

As MANY people have encountered this same problem and it seems fairly fundamental to getting hibernate to work (for those of us with problems, at least), further help on this would be greatly appreciated.

I'm a bit busy for the next several hours, but I'll take another look at this tonight or tomorrow. By the way, the code in the DefaultFlushEntityEventListener.checkId() looks like it is swapping the "from" and "to" in the message, so the first message should read


which, of course, would make more sense.

Is there a solution for this? Did you guys find the problem? Could you help me?

I'm having this problem too:

I've been a big fan of the hibernate project for a long time (although not a user until recently), so I am that much more disappointed that I have seen so many unanswered posts about this same problem.

if there is an experienced person on the hibernate development team who could give us an answer, it would be greatly appreciated.

I have not been able to duplicate this error. Can you post enough info for me to be able to generate this error? Slim down the code to an absolute minimum.

i'm not sure if it's possible to slim down the code more than I already have. look at the original posting. there's only about 20 lines of code and 3 lines from the mapping file. if that is not slim enough, i'm not sure how to proceed.

The problem with my code, I think it was because I had more than one thread altering the same objects...

I just resolved this problem, the issue was that I had the wrong data type for my primary key in the entity's .hbm.xml file.

The underlying database table (SQL Server) has a primary key column of bigint. This column is also an identity field.

My original mapping config looked like this:


with this configuration I received the exception
identifier of an instance of ...[class name]... was altered from 1670012 to 1670012

I modified the mapping config to be:


and it works now.

I had the same issue.

In my circumstance, I was using "assigned" primary keys (i.e. not auto-generated ones). If a child record was added to the collection of a parent before the primary key value had been assigned, I would get this error when saving the parent (which had a cascade action to save its child entries).

The solutiuon was to ensure that the primary key value was assigned to the child before adding the child to the parent's collection.

Same issue! Expert could you answer the question!
https://forum.hibernate.org/viewtopic.php?f=1&t=999557

plz use this in the hbm.xml file for id generator :

<generator class="native" />

The generator causes a conflict in the Auto Increment option of MYSQL and Hibnerate.
Hope this will resolve the problem.


Abdullah Wasi

I am having same problem.
I have Student object which holds reference to ID of Address object.
I update Student object and want to change the reference to another instance of Address Object. Say want to change ID from 2 to 3.
Hibernate throws exception
org.hibernate.HibernateException: identifier of an instance of Address was altered from 2 to 3
at org.hibernate.event.def.DefaultFlushEntityEventListener.checkId(DefaultFlushEntityEventListener.java:58)
at org.hibernate.event.def.DefaultFlushEntityEventListener.getValues(DefaultFlushEntityEventListener.java:164)
at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:120)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:196)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:76)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:26)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:343)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)

The mappings I have are
there is no cascade here, so i am updating the parent , but updating reference in child.

In the session I do
start transaction
studentObject = session.get(StudentClass, id);
and update the AddressID from 2 to 3
call session.saveOrUpdate(StudentClass, studentObject);
and commit Transaction

<class name="com.san.Student" table="Student" dynamic-insert="true" mutable="true" polymorphism="implicit" dynamic-update="false" select-before-update="false" optimistic-lock="version">
<id name="ID" type="java.lang.Long" column="ID">
<generator class="native"/>
</id>
<many-to-one name="StudentAddress" name="com.san.Address" fetch="join" unique="true" update="true" insert="true" optimistic-lock="true" not-found="exception" embed-xml="true">
<column name="AddressID" not-null="true"/>
</many-to-one>
<property name="Name" type="java.lang.String" column="Name" unique="false" optimistic-lock="true" lazy="false" generated="never"/>
<property name="LastName" type="java.lang.String" column="Description" unique="false" optimistic-lock="true" lazy="false" generated="never"/>
</class>

<class name="com.san.Address" table="Address" dynamic-insert="true" mutable="true" polymorphism="implicit" dynamic-update="false" select-before-update="false" optimistic-lock="version">
<id name="ID" type="java.lang.Long" column="ID">
<generator class="native"/>
</id>

<property name="Add1" type="java.lang.String" column="Name" unique="false" optimistic-lock="true" lazy="false" generated="never"/>
<property name="Add2" type="java.lang.String" column="Description" unique="false" optimistic-lock="true" lazy="false" generated="never"/>
</class>


What could be the problem?

Hi All,

I have faced this issue quite recently and the only thing I did wrong was, I was declaring the type of the identity column as "int" in hbm files.

I have changed it to LONG and everything is working fine.


Hope this helps someone !!!