从查询结果中减去1

Question

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

我想从count(P.pID)的任何结果中减去“1”。因此，例如，如果P.pID的值为10，则输出9 ...... ??

Answer 1

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

Answer 2

怎么样？

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

Answer 3

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