MYSQL GROUP BY CONCAT / 필드 합치기

Basically the question is how to get from this:

id    string
1          A
1          B
2          C

to this:

id    string
1          A B
2          C

출저 : http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat

참고 : http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat

SELECT id, GROUP_CONCAT(string SEPARATOR ' ') FROM table GROUP BY id;