Anders

Actually, I tend to think that business rules like your's (have to supply an unused order number when creating, in this case) should always be enforced in the DD class.

Putting them in the UI code, or, as in this case, adding code to a web service to do that, will tend to produce inconsistent enforcement across the overall codebase.

You should have just one set of DDs, which all projects use, even across different workspaces. I favour using a single DDSrc directory which all workspaces for the system involved share (by modifying the workspace path for DDSrc).

The problem, of course, was that in "the old days", post VDF4 (so once we had DDs), but before web apps, developers might have felt that it was a choice to put such code where it was most convenient (involving least brain-strain ), perhaps used to doing things in the old procedural style where there was only the UI code.

Mike