转自:https://www.cnblogs.com/David3290/p/11378579.html
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 ) SE
基本建表语句
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');
使用情景:假定a表某一列的数据格式是 逗号分隔 的 a,b,c,想将之变成三行数据