select f.name as name,
group_concat(distinct m.name) as module
from files f
inner join module m
on (f.module_id = m.id)
where f.name = ?
and f.environment = ?
concat 连接字符串
group_concat 连接同组字符串
原文：http://www.cnblogs.com/Raymond-Yang/p/5064189.html