My original thought was that there would be no rows returned as this was an insert.

But I then thought that was silly, and I was being unfair on the questioner who had made an honest and obvious mistake - there are too many questions that provoke pedantic discussions whyen the meaning of the question is clear.

So I answered the question as if it had been 'how many rows are inserted'.

Given recent questions, I think this was a fair assumption to make.