Illegal attempt to associate ...

nosnos · **Joined:** Wed Aug 27, 2003 5:35 am **Posts:** 5

Hi,

I think it is a basic problem, but I don't know how to solve it.

I have a class generate by hbm2java, that contains lazy instanciation.

When I try to delete it , hibernate throw an exception with this msg :
Illegal attempt to associate a collection with two open sessions

It is sure that it is due to the lazy because I open a new session to delete this object, but How can I delete this class .?

thx a lot
nosnos

gavin · **Posted:** Wed Aug 27, 2003 5:55 am

It helps to read the exception message. You can not have a collection associated with two open sessions. This exception probably occurred because you forgot to close the provious session. It has nothing to do with laziness.

Stueckdeckungsbeitrag · **Joined:** Mon Jun 11, 2007 12:32 pm **Posts:** 1

Hello,

I got the same problem today and found a solution.
In my situation the cascade attribute in all many-to-one relations caused the exception.

greg_barton · **Posted:** Sat Jun 16, 2007 11:50 am

Same here. In my case I was attempting Session.saveOrUpdate() on a detached object. I opened one session+transaction per object and made one call to saveOrUpdate(). I was still getting "Illegal attempt to associate a collection with two open sessions." The only solution that's worked (so far) is setting cascade="none" on various many-to-one mappings. I also want to try replacing saveOrUpdate() with merge(), but I haven't been able to test that yet,