Hello Tuscany, I am working on building a DAS implementation for an old hierarchical database and am looking at Tuscany as *the* DAS reference implementation. Several issues around applyChanges are troubling me and I'm hoping to start a dialog to address them (or even better get a really obvious answer that I'm missing)
When a client returns a modified DataGraph back to a DAS instance, that DAS needs some basic information such as which Database, which Table, and which specific row(s) the now modified data originally came from before it can start comparing old values, etc. How does a DAS get this high level information from an incoming DataGraph? Is there a way to somehow tie the incoming DataGraph back to the initial Command that produced it? Holding state in the DAS sounds like cheating since it would break the fundamental SDO concepts, plus the SDO spec mentions being able to take a DataGraph produced by one DAS and return it to another for changes. Assuming we know the database and table somehow, what happens in the case where the primary key(s) are not included in the DataObject? do we put them in the DataObject anyways during retrieval. And even so what about the case where the table has no unique primary key (is that even legal in the relational world)? Thanks, Chris
