Hello OJB gurus: I'm having a repeatable problem with ODMG Transaction locking and unwanted database insertions when I use proxy collections.
Here is a description of my environment: [1] OJB 1.0.3 [2] implicitLocking=false in my OJB.properties [3] I have an object of type Parent with a Collection of objects of type Child. The Collection is via an indirection-table. Neither Parent nor Child is a proxiable object (meaning that in the <class-descriptor> elements for both Parent and Child, the "proxy" attribute is NOT specified). [4] The Parent collection of Child objects IS proxied via a Collection proxy. This means that the "children" <collection-descriptor>'s "proxy" attribute is set to true. Here is what happens in pseudo code in run time: [1] Opening persistent state: A given Parent object instance, parentA, has one Child instance, ChildA, in it's Collection of children. [2] A new ODMG Transaction is begun and parentA is retrieved from the database. At this point, the Collection of Child objects (just childA) has not yet been materialized. [3] parentA is WRITE locked to the current transaction. [4] A new child, childB, is created and WRITE locked to the transaction. [5] childB is added to the Collection of parentA's children via parentA.getChildren().add( childB ). I assume at this point the actual Collection of children was materialized by the proxy during the call to the getChildren() method. [6] The transaction is committed and an SQLException occurs when the Child primary key constraint is violated because OJB tries to re-insert childA into the database. The Exception also occurs even if I WRITE lock childA to the current transaction too before step 5. However, the exception does NOT occur if I set the "proxy" attribute in Parent's children <collection-descriptor> to false. This leads me to believe that there is some state check when an object is locked to a Transaction that is missing the existence of the proxied collection of Children. When the proxied collection of Children is materialized during the transaction, OJB incorrectly assumes that the materialized childA also needs to be written to the database. Is this a bug or the intended behavior? I assume a work around would be to have Child be a proxiable object and remove the Collection proxy from Parent to Child, but I would rather not if I didn't have to. Thanks for the help, Jon French Programmer ECOS Development Team [EMAIL PROTECTED] 970-226-9290
