If you book a flight as part of a mileage run that included the following:

DTW to XXX (DL Flight 123, say) and then take XXX to DTW listed also as DL flight 123, all on the same day (and same equipment), how will your skymiles account get credited? In essence, you have flight 123 from DTW to DTW. Any experience with this? Will you get two segments with flight 123 (one DTW to XXX, the other XXX to DTW), or no credit at all?