根据相应条件抽出相应count数（myCount）

抽出总count数(totalCount)

计算百分比：myCount / totalCount * 100

四舍五入：使用ROUND函数ROUND(number，要保留的小数位)，ROUND(myCount / totalCount * 100,1)

下面给出示例供参考：

    SELECT ROUND(T1.co/T2.totalCo*100,1)
    FROM 
     (SELECT COUNT(*) AS co
        FROM fup1
       WHERE fup1.PERIOD6 = 1
       AND fup1.P6CCTCHK = 2) T1,
     (SELECT COUNT(*) AS totalCo
       FROM fup1
       WHERE fup1.PERIOD6 = 1)T2;

Mysql求百分比