请在下面的查询中使用

select col2, GROUP_CONCAT(col3) from data group by col2;

下面是测试用例，

https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=ab35e8d66ffe3ac6436c17faf97 / a>

https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=ab35e8d66ffe3ac6436c17faf97ee9af