Subtract 1 From Query Result

Question

SELECT count(P.pID)
FROM Department D, Professor P
WHERE D.dID = ? AND P.dID = D.dID;

I would like to subtract '1' from any result for count(P.pID) . So for instance if value of P.pID is 10, it would output 9... ??

Answer 1

SELECT count(P.pID) - 1 as pID_count 
FROM Department D, Professor P 
WHERE D.dID = ? AND P.dID = D.dID;