MySQL - 计算相关记录的百分比和计数

coder 2023-10-22 原文

请需要帮助来完成代码以执行以下操作:

计算具体记录的票数和百分比，是一个电影网站，用户可以在这里观看和投票电影，那么该网站应该更多地展示所有电影以降低用户的票数，这里详细说明什么我正在尝试做。

1)计算每部电影的票数。

2)通过单独的“They are totally 3 table[votes]”获取每部电影的得票数，如:

电影 1 共有 100 票，20% 的用户认为Regular，30% 的用户认为Good，50% 的用户认为很好。

3) 获取“3 of table [votes]”之间的最大票数的百分比，如果用户投票更多的是电影非常好，我必须计算那个百分比, 所以我们可以创建一个小 donut 或图形，向用户展示比你喜欢的更多的电影和类型转换，例如:

该片被评为电影1，总票数450票，占用户评分总票数的50%。

到目前为止我已经这样做了:

SELECT
    M.name AS title_movie,
    M.year AS premiere,
    G.name AS gender,
    COUNT(MHR.vote_id) AS total_voting_movie
FROM movies M
LEFT JOIN gender G ON M.gender_id = G.id
LEFT JOIN movies_has_rating MHR ON M.id = MHR.movie_id
GROUP BY M.id
ORDER BY M.id DESC

图表数据库:

整个数据库的完整代码:

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for gender
-- ----------------------------
DROP TABLE IF EXISTS `gender`;
CREATE TABLE `gender` (
  `id` int(11) NOT NULL,
  `name` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

-- ----------------------------
-- Records of gender
-- ----------------------------
INSERT INTO `gender` VALUES ('1', 'Action');
INSERT INTO `gender` VALUES ('2', 'Musical');
INSERT INTO `gender` VALUES ('3', 'Sci Fi');

-- ----------------------------
-- Table structure for movies
-- ----------------------------
DROP TABLE IF EXISTS `movies`;
CREATE TABLE `movies` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `year` varchar(255) DEFAULT NULL,
  `gender_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=latin1;

-- ----------------------------
-- Records of movies
-- ----------------------------
INSERT INTO `movies` VALUES ('1', 'Alien', '1979', '1');
INSERT INTO `movies` VALUES ('2', 'Aliens', '1986', '1');
INSERT INTO `movies` VALUES ('3', 'Moulin Rouge', '2001', '3');
INSERT INTO `movies` VALUES ('4', 'Guys and Dolls', '1955', '3');
INSERT INTO `movies` VALUES ('5', 'Mama Mia', '1970', '3');
INSERT INTO `movies` VALUES ('6', 'Starman', '1984', '1');
INSERT INTO `movies` VALUES ('7', 'Tron', '1982', '1');
INSERT INTO `movies` VALUES ('8', 'The Matrix', '1988', '2');

-- ----------------------------
-- Table structure for movies_has_rating
-- ----------------------------
DROP TABLE IF EXISTS `movies_has_rating`;
CREATE TABLE `movies_has_rating` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `movie_id` int(11) NOT NULL,
  `vote_id` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=156 DEFAULT CHARSET=latin1;

-- ----------------------------
-- Records of movies_has_rating
-- ----------------------------
INSERT INTO `movies_has_rating` VALUES ('1', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('2', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('3', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('4', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('5', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('6', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('7', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('8', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('9', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('10', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('11', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('12', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('13', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('14', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('15', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('16', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('17', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('18', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('19', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('20', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('21', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('22', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('23', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('24', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('25', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('26', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('27', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('28', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('29', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('30', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('31', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('32', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('33', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('34', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('35', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('36', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('37', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('38', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('39', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('40', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('41', '1', '2');
INSERT INTO `movies_has_rating` VALUES ('42', '1', '3');
INSERT INTO `movies_has_rating` VALUES ('43', '1', '1');
INSERT INTO `movies_has_rating` VALUES ('44', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('45', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('46', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('47', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('48', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('49', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('50', '2', '1');
INSERT INTO `movies_has_rating` VALUES ('51', '2', '1');
INSERT INTO `movies_has_rating` VALUES ('52', '2', '1');
INSERT INTO `movies_has_rating` VALUES ('53', '2', '1');
INSERT INTO `movies_has_rating` VALUES ('54', '2', '1');
INSERT INTO `movies_has_rating` VALUES ('55', '2', '1');
INSERT INTO `movies_has_rating` VALUES ('56', '2', '1');
INSERT INTO `movies_has_rating` VALUES ('57', '2', '1');
INSERT INTO `movies_has_rating` VALUES ('58', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('59', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('60', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('61', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('62', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('63', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('64', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('65', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('66', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('67', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('68', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('69', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('70', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('71', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('72', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('73', '2', '3');
INSERT INTO `movies_has_rating` VALUES ('74', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('75', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('76', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('77', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('78', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('79', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('80', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('81', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('82', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('83', '2', '2');
INSERT INTO `movies_has_rating` VALUES ('84', '2', '1');
INSERT INTO `movies_has_rating` VALUES ('85', '3', '1');
INSERT INTO `movies_has_rating` VALUES ('86', '3', '1');
INSERT INTO `movies_has_rating` VALUES ('87', '3', '1');
INSERT INTO `movies_has_rating` VALUES ('88', '3', '1');
INSERT INTO `movies_has_rating` VALUES ('89', '3', '2');
INSERT INTO `movies_has_rating` VALUES ('90', '3', '3');
INSERT INTO `movies_has_rating` VALUES ('91', '4', '2');
INSERT INTO `movies_has_rating` VALUES ('92', '4', '1');
INSERT INTO `movies_has_rating` VALUES ('93', '4', '2');
INSERT INTO `movies_has_rating` VALUES ('94', '4', '2');
INSERT INTO `movies_has_rating` VALUES ('95', '4', '2');
INSERT INTO `movies_has_rating` VALUES ('96', '4', '3');
INSERT INTO `movies_has_rating` VALUES ('97', '4', '3');
INSERT INTO `movies_has_rating` VALUES ('98', '4', '1');
INSERT INTO `movies_has_rating` VALUES ('99', '4', '1');
INSERT INTO `movies_has_rating` VALUES ('100', '4', '1');
INSERT INTO `movies_has_rating` VALUES ('101', '4', '1');
INSERT INTO `movies_has_rating` VALUES ('102', '4', '2');
INSERT INTO `movies_has_rating` VALUES ('103', '4', '3');
INSERT INTO `movies_has_rating` VALUES ('104', '4', '2');
INSERT INTO `movies_has_rating` VALUES ('105', '4', '3');
INSERT INTO `movies_has_rating` VALUES ('106', '4', '3');
INSERT INTO `movies_has_rating` VALUES ('107', '4', '3');
INSERT INTO `movies_has_rating` VALUES ('108', '4', '2');
INSERT INTO `movies_has_rating` VALUES ('109', '4', '2');
INSERT INTO `movies_has_rating` VALUES ('110', '4', '2');
INSERT INTO `movies_has_rating` VALUES ('111', '5', '2');
INSERT INTO `movies_has_rating` VALUES ('112', '5', '2');
INSERT INTO `movies_has_rating` VALUES ('113', '5', '2');
INSERT INTO `movies_has_rating` VALUES ('114', '5', '2');
INSERT INTO `movies_has_rating` VALUES ('115', '5', '2');
INSERT INTO `movies_has_rating` VALUES ('116', '5', '2');
INSERT INTO `movies_has_rating` VALUES ('117', '5', '2');
INSERT INTO `movies_has_rating` VALUES ('118', '5', '2');
INSERT INTO `movies_has_rating` VALUES ('119', '5', '2');
INSERT INTO `movies_has_rating` VALUES ('120', '5', '3');
INSERT INTO `movies_has_rating` VALUES ('121', '5', '3');
INSERT INTO `movies_has_rating` VALUES ('122', '5', '3');
INSERT INTO `movies_has_rating` VALUES ('123', '5', '3');
INSERT INTO `movies_has_rating` VALUES ('124', '6', '3');
INSERT INTO `movies_has_rating` VALUES ('125', '6', '3');
INSERT INTO `movies_has_rating` VALUES ('130', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('131', '8', '1');
INSERT INTO `movies_has_rating` VALUES ('132', '8', '1');
INSERT INTO `movies_has_rating` VALUES ('133', '8', '1');
INSERT INTO `movies_has_rating` VALUES ('134', '8', '1');
INSERT INTO `movies_has_rating` VALUES ('135', '8', '1');
INSERT INTO `movies_has_rating` VALUES ('136', '8', '1');
INSERT INTO `movies_has_rating` VALUES ('137', '8', '1');
INSERT INTO `movies_has_rating` VALUES ('138', '8', '2');
INSERT INTO `movies_has_rating` VALUES ('139', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('140', '8', '2');
INSERT INTO `movies_has_rating` VALUES ('141', '8', '2');
INSERT INTO `movies_has_rating` VALUES ('142', '8', '2');
INSERT INTO `movies_has_rating` VALUES ('143', '8', '2');
INSERT INTO `movies_has_rating` VALUES ('144', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('145', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('146', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('147', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('148', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('149', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('150', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('151', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('152', '8', '3');
INSERT INTO `movies_has_rating` VALUES ('153', '8', '3');

-- ----------------------------
-- Table structure for users
-- ----------------------------
DROP TABLE IF EXISTS `users`;
CREATE TABLE `users` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `email` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=latin1;

-- ----------------------------
-- Records of users
-- ----------------------------
INSERT INTO `users` VALUES ('1', 'Name user 1', '1@1.com');
INSERT INTO `users` VALUES ('2', 'Name user 2', '2@2.com');
INSERT INTO `users` VALUES ('3', 'Name user 3', '3@3.com');

-- ----------------------------
-- Table structure for votes
-- ----------------------------
DROP TABLE IF EXISTS `votes`;
CREATE TABLE `votes` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=latin1;

-- ----------------------------
-- Records of votes
-- ----------------------------
INSERT INTO `votes` VALUES ('1', 'Very good');
INSERT INTO `votes` VALUES ('2', 'Good');
INSERT INTO `votes` VALUES ('3', 'Regular');

非常感谢您的支持，非常感谢。

最佳答案

您的第三部分不清楚。但是第二部分可以通过以下方式解决:

SELECT
    M.name AS title_movie,
    M.year AS premiere,
    G.name AS gender,
    COUNT(MHR.vote_id) AS total_voting,
    -- 2)
    COUNT(MHR.vote_id = 1 OR NULL) AS count_very_good,
    COUNT(MHR.vote_id = 2 OR NULL) AS count_good,
    COUNT(MHR.vote_id = 3 OR NULL) AS count_regular
FROM movies M
LEFT JOIN gender G ON M.gender_id = G.id
LEFT JOIN movies_has_rating MHR ON M.id = MHR.movie_id
GROUP BY M.id
ORDER BY M.id DESC

http://sqlfiddle.com/#!9/5ba403/5

我相信您知道如何根据该结果计算百分比。

更新:因此 OP 要求确定计数最高的投票类型并计算其在 SQL 中的百分比。您可以(但不应该)使用以下查询来完成此操作:

SELECT t.*, 
    CASE
        WHEN highest_votes_id = 1
            THEN 100 * count_very_good / total_voting
        WHEN highest_votes_id = 2
            THEN 100 * count_good / total_voting
        WHEN highest_votes_id = 3
            THEN 100 * count_regular / total_voting
    END AS highest_votes_percentage
FROM (  
    SELECT t.*,
        CASE
            WHEN count_regular > count_good AND count_regular > count_very_good
                THEN 3
            WHEN count_good > count_very_good
                THEN 2
            ELSE 1
        END AS highest_votes_id
    FROM (
        SELECT
            M.id,
            M.name AS title_movie,
            M.year AS premiere,
            G.name AS gender,
            COUNT(MHR.vote_id) AS total_voting,
            COUNT(MHR.vote_id = 1 OR NULL) AS count_very_good,
            COUNT(MHR.vote_id = 2 OR NULL) AS count_good,
            COUNT(MHR.vote_id = 3 OR NULL) AS count_regular
        FROM movies M
        LEFT JOIN gender G ON M.gender_id = G.id
        LEFT JOIN movies_has_rating MHR ON M.id = MHR.movie_id
        GROUP BY M.id
    ) t
) t
ORDER BY t.id DESC

http://sqlfiddle.com/#!9/5ba403/7

无论您如何在 SQL 中解决该问题，最终都会得到不合理的丑陋代码。你最好用 PHP 来做。

if ($row['count_regular'] > $row['count_good'] &&
    $row['count_regular'] > $row['count_very_good']
) {
    $highestVoteType  = 'Regular';
    $highestVoteCount = $row['count_regular'];
} elseif ($row['count_good'] > $row['count_very_good']) {
    $highestVoteType  = 'Good';
    $highestVoteCount = $row['count_good'];
} else {
    $highestVoteType  = 'Very Good';
    $highestVoteCount = $row['count_very_good'];
}
if ($row['total_voting'] != 0) {
    $highestVotePercantage = 100 * $highestVoteCount / $row['total_voting'];
} else {
    $highestVotePercantage = null;
}

关于MySQL - 计算相关记录的百分比和计数，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35529403/

MySQL 计算 39 movies_has_rating movies sql count average

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