我需要帮助从两个查询中减去结果

    DECLARE @TotalQuestions int;
DECLARE @CorrectQuestions int;
DECLARE @IncorrectQuestions int;

SELECT (
  SET CorrectQuestion = SELECT COUNT( WiningComment)
    FROM Threads
    WHERE WiningComment IN (SELECT CommentsID
    FROM Comments
    WHERE  UsersID=@UserID)
) as 'WinningAnswers',
(
    SET TotalQuestions =  SELECT COUNT(CommentsID)
    FROM  Comments
    WHERE  UsersID=@UserID
) as 'TotalAnswers'
(
  SELECT  (TotalQuestions-CorrectQuestions ) //I am not sure about this part!!
) as 'IncorrectQuestions' 
    DECLARE @TotalQuestions int;
DECLARE @Corre