将类似的查询结果合并为一行

Question

我有

ID username group
1  philip   football
2  george   baseball
3  alice    football
4  ani      football
5  george   football

并尝试制作此

username   group
philip     football
george     baseball, football
alice      football
ani        football

换句话说，我想把grop idetms组合成一个字符串，就像这里的“baysboll，football”

Answer 1

您需要GROUP_CONCAT功能

 select username, GROUP_CONCAT(group) FROM table GROUP BY Username

Answer 2

不要忘记使用反引号转义列Group以避免语法错误。 GROUP是 Reserved Keyword 。

SELECT username, GROUP_CONCAT(`group`) 
FROM table
GROUP BY userName