Asking user input, why?

I am fairly new to SQL but I have a query that asks for user input no matter how I try to code it. Here is what I have:

SELECT DISTINCTROW Roundedmm, Sum([Incoming].[Number of Pieces]) AS num_pieces
FROM Incoming
GROUP BY Roundedmm;

Why would this be asking for a user input for Roundedmm? I know this must be a simple issue but any help would be great.