i have a one-to-many mapping and when i m trying to add the object to the list in the parent object i m getting the following error

please help me out with this
what could be the possible reason for the same

You implement equals and hashcode?

The problem was that i was removing all the child objects from the list in the parent and then inserting so in the same session it was not able to commit the delete and was throwing this error.

i actually did a workaround ...implemented the equals and hashcode methods and updated those child objects that are present already with the same composite identifier in the list and if not found i inserted the object.

can u suggest me a better way to do this ??

Instead of save or update use merge.

thanks for the reply
could u please send me an example of merge

Hi Sameer11sep,

pass employeeGroup which contain collection of employee (with out ID)

then in method select employeeGroup from DB by employeeGroup.ID
in employeeGroupDB .And do like this.

if (employeeGroupDB == null) {
session.saveOrUpdate(employeeGroup);
} else {
session.merge(employeeGroup);
}
session.flush();
session.clear();