SELECT yt.userid,
GROUP_CONCAT(yt.col SEPARATOR ' ') AS combined
FROM YOUR_TABLE yt
GROUP BY yt.userid
默认的分隔符是逗号(“,”),因此您需要指定单个空格的SEPARATOR以获得所需的输出。
如果要确保GROUP_CONCAT中值的顺序,请使用:
SELECT yt.userid,
GROUP_CONCAT(yt.col ORDER BY yt.col SEPARATOR ' ') AS combined
FROM YOUR_TABLE yt
GROUP BY yt.userid