ASP.NET - uniquely identify session objects with database generated ids

I have an ob开发者_Go百科ject with multiple collections that is retrieved from a WCF service and stored in the session.

The collections are bound to ListViews on the page, with a final submit button at the bottom.

I want to be able to make changes to this object in the session (add/edit items in the collections), without persisting the changes until the final submit button is clicked.

The problem I'm having is that the ids are created in the db, so all newly added items will have an id of 0. I don't see a way to uniquely identify the collection items unless I add something like a clientID field to the datacontract. I feel like I'm missing something really obvious here.

If these are auto-generated identity values, you can insert additionally guids for each entry.