如何在MySQL中连接结果集？

Question

我想将逗号作为分隔符字符串加入MySQL中的集合中返回的结果.

例如,set return包含:

COLUMN_X
john
jerry
maria
joseph
gugla

我想收到的结果是:

COLUMN_X-concat
john,jerry,maria,joseph,gugla

那可能吗？谢谢.

SELECT CONCAT(rooms.ID,",") FROM rooms AS rooms LEFT JOIN inter AS i ON rooms.ID=i.value WHERE xxx=999

不起作用,因为它返回单独的结果.

Answer 1

SELECT GROUP_CONCAT(COLUMN_X SEPARATOR ',') FROM <<table>> GROUP BY NULL

见GROUP_CONCAT.