mysql数据库中某项其中一个值在该项排第几,百分几

SELECT X.USER_ID, X.TOTAL_NO, X.ORDER_NO, X.ORDER_NO / X.TOTAL_NO AS PERCENTAGE_NO
FROM (SELECT @rowNum := @rowNum + 1 AS ORDER_NO, @rowCount AS TOTAL_NO, USER_ID
    FROM T_SD_USER, (SELECT @rowNum := 0
        ) b, (SELECT @rowCount := (
                SELECT COUNT(*)
                FROM T_SD_USER
                )
        ) c
    ORDER BY USER_ID DESC
    ) X
WHERE USER_ID = 3008

SELECT X.COMMENT_ID, X.TOTAL_NO, ORDER_NO, IFNULL(X.ORDER_NO / X.TOTAL_NO, 1) AS PERCENTAGE_NO
FROM (SELECT @rowNum := @rowNum + 1 AS ORDER_NO, @rowCount AS TOTAL_NO, t.COMMENT_ID, t.COMMENT_SPENDING
    FROM T_SD_COMMENT t, (SELECT @rowNum := 0
        ) b, (SELECT @rowCount := (
                SELECT COUNT(*)
                FROM T_SD_COMMENT
                WHERE to_days(CREATE_TIME) >= to_days(now())
                )
        ) c
    ORDER BY CREATE_TIME DESC
    ) X
WHERE COMMENT_ID = 15