根据相应条件统计需要的count

查询总count数(totalCount)

计算百分比：count / totalCount * 100

表设计：

CREATE TABLE `topic_exercise` (
  `id` bigint(11) NOT NULL,
  `topic_id` bigint(11) NOT NULL COMMENT '试题id',
  `user_id` bigint(11) NOT NULL COMMENT '用户id',
  `user_answ` varchar(255) NOT NULL,
  `topic_answ` varchar(255) DEFAULT NULL COMMENT '试题答案',
  `serial` bigint(11) NOT NULL COMMENT '用户练习模块答题记录序号',
  `records_id` bigint(11) DEFAULT NULL COMMENT '练习记录列表id',
  `status` tinyint(4) DEFAULT NULL COMMENT '0 错误  1正确',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

SQL写法： 

SELECT
  ROUND(T1.co / T2.totalCo * 100, 1)  as accuracy
FROM
  (
    SELECT
      COUNT(*) AS co
    FROM
      topic_exercise
    WHERE
      user_id = 844228520938668032
    AND user_answ=topic_answ
  ) T1,
  (
    SELECT
      COUNT(*) AS totalCo
    FROM
      topic_exercise
    WHERE
      user_id = 844228520938668032
  ) T2;

查询结果：

MYSQL求2个参数之间的正确率百分比_sql