关于MySQL的行转列

需求：

1、原始数据

2、处理结果演示

3、对应的sql语句

SELECT
    a.id,
    a. NAME,
    substring_index(
        substring_index(
            a.shareholder,
            ',',
            b.help_topic_id + 1
        ),
        ',' ,- 1
    ) AS shareholder
FROM
    company a
JOIN mysql.help_topic b ON b.help_topic_id < (
    length(a.shareholder) - length(
        REPLACE (a.shareholder, ',', '')
    ) + 1
)

4、附录

基本表建立语句：

CREATE TABLE `company` (
  `id` int(20) DEFAULT NULL,
  `name` varchar(100) DEFAULT NULL,
  `shareholder` varchar(100) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `company` VALUES ('1', '阿里巴巴', '马云');
INSERT INTO `company` VALUES ('2', '淘宝', '马云,孙正义');