如果用withNewSession包装，grails创建条件非唯一对象错误

Question

I have criteria that looks like this

  //Inventory.withNewSession{
    Set inventory=Inventory.withCriteria{
       setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY)
       inventoryDetail{
           eq('userAdded',true)
       }
       ...
     }
//}

If I wrap that in a withNewSession I get duplicate key and non unique object in the session errors. If I don't use withNewSession, it works.

Why?

Answer 1

If you already had a session and loaded object with id=1 (eg), and then created a new session and loaded that same object. When the new session block ends, the hibernate session joins the existing session (am I saying this right?) and now you have your both objects loaded with the same ID.

I'm not sure why you're using withNewSession here, is there a path that this may execute without a hibernate session? Are you trying, as TDC suggests, to isolate this transactionally?

Answer 2

maybe try to use replace withNewSession with withTransaction?

Inventory.withTransaction{
    Set inventory=Inventory.withCriteria{
       setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY)
       inventoryDetail{
           eq('userAdded',true)
       }
     }
}