StaleObjectStateError.....

Okay, I have added my hibernate mapping below..and more explanation on this issue. I really need help with this...

I have an object lets say its called House. This object has a many to one relationship with another object called Father :).
This relationship is bi-directional. The id for Father is auto-generated using GUID. I am calling a DAO object from a session bean where the transaction is container managed and set to required.

In the web tier, I get a reference to the House object, update some fields and either add a Father, update the father or remove the Father (house.setFather(null)).

Then, I make a call to one method on a House DAO called updateHouse that handles all these calls in the following way:

updateHouse(House h){

if(h.getFather()!=null){
//we have a father
if(h.getFather().getFatherId()!=null){
//this father is being updated
session.update(h.getFather());
}else{
//this father is being created for the House
session.save(h.getFather();
}
}

//The house has other properties that could also be updated
session.update(h);
}

Now when I run this code, I get a StaleObjectStateError on the Father object telling me the following:


Problem updating House: my.package.House@2c14f9[houseId=1] and the Exception Msg is:
my.package.util.DataAccessException: net.sf.hibernate.StaleObjectStateException: Row
was updated or deleted by another transaction (or unsaved-value mapping was incorrect) for my.package.Father instance with identifier: 402880e5f805977600f807d5f42b0004

I am using Hibernate 2.0.2 and following are my mapping files:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping>

<!--
Created by Middlegen Hibernate plugin

http://boss.bekk.no/boss/middlegen/
http://hibernate.sourceforge.net/
-->

<class
name="my.package.House"
table="SCHOOL"
proxy="my.package.House"
dynamic-update="true"
>
<meta attribute="implements">net.sf.hibernate.Lifecycle</meta>
<meta attribute="implements">net.sf.hibernate.Validatable</meta>
<id
name="houseId"
type="java.lang.Integer"
column="HOUSE_ID"
unsaved-value="null"
>
<generator class="assigned" />
</id>

<timestamp
column="user_dt"
name="userDt"
/>

<property
name="userId"
type="java.lang.String"
column="user_id"
length="8"
/>

<!-- associations -->
<!--one-to-one association to Teacher -->
<many-to-one
name="principal"
class="my.package.Father"
not-null="false"
>
<column name="principal_id" />
</many-to-one>

</class>

<class
name="my.package.Father"
table="TEACHER"
proxy="my.package.Father"
dynamic-update="true"
>
<meta attribute="implements">net.sf.hibernate.Lifecycle</meta>
<meta attribute="implements">net.sf.hibernate.Validatable</meta>
<id
name="fatherId"
type="java.lang.String"
column="FATHER_ID"
unsaved-value="none"
>
<generator class="uuid.hex" />
</id>
<property
name="name"
type="java.lang.String"
column="name"
not-null="false"
length="100"
/>
<property
name="comment"
type="java.lang.String"
column="comment"
not-null="false"
length="3500"
/>

</hibernate-mapping>


My classes were auto-generated by hbm2java. This has taken all weekend and I am not sure why Hibernate is doing this..

Have a look at the userDt column. You declared this column as timestamp element in the map. This causes Hibernate to compare the value of your object with the value stored at database while trying to store the object. If the value at the database is "newer", than you get the StaleObjectStateErrorException.