Many to many problem

adr · **Joined:** Tue Mar 21, 2006 4:19 am **Posts:** 15

Hi guys!
I have association user - products many to many.
I have a user bean with collection of products. I want to create a new record of this user in the db but the hibernate does not connect the products to the new record here is the code:

Code:

tx = session.beginTransaction();
user.setIsHistory("1");
session.update(user);
tx.commit();

session.evict(user);

tx = session.beginTransaction();
user.setIsHistory("0");
session.save(user);
tx.commit();

Any suggestions?

ChristianS · **Posted:** Tue Aug 22, 2006 1:41 pm

If its a new record then you should use saveOrUpdate() method I suppose.
edited: sorry, didnt see that you only have problems with the relation of the objects, not the save of them, forget this post.

kochcp · **Posted:** Tue Aug 22, 2006 2:16 pm

you neet to set them in the object. I have no idea which is the parent or what, but you need to call something like

Code:

beginTransaction()
Child c = new Child();
c.setParent(parent)
Parent.addChild(c)
update(Parent)
commit()

adr · **Joined:** Tue Mar 21, 2006 4:19 am **Posts:** 15

Thx but i`m already doing this
i`ll paste the entire code here to see the whole situation:

this is my create method code:

Code:

tx = session.beginTransaction();
rtDTO.setIsHistory("1");
session.update(rtDTO);
tx.commit();
         
session.evict(rtDTO);
tx = session.beginTransaction();
rtDTO.setIsHistory("0");
// creates a new record in the database with rtDTO
session.save(rtDTO);
connectTraderToProducts(rtDTO);
tx.commit();

In this method when i invoke save() method the id is changed to the
last+1 in the table. But when i invoke the

here is the method "connectTraderToProducts" where i connect many to many association

Code:

List products = (List) rtDTO.getCommonExciseProductMany();
for (int i = 0; i < products.size(); i++) {
Product product = (Product ) products.get(i);
ArrayList existed = new ArrayList(product.getTraders());

/* ------

When i retrieve the traders for this product 
the id of the Trader is rolled back to the previous one before
i evict() it from the session and invoke save() method
any idea why this happens?

*/ ---

boolean exist = false;
for (int j = 0; j < existed.size(); j++) {
   Trader rt = (Trader) existed.get(j);
      if (rt.getId().equals(rtDTO.getId())) {
          exist = true;
      }
   }
   if (!exist) {
       product.getTraders().add(rtDTO);
   }
}