select DATE_FORMAT(upday, '%Y年%m月') as YM, DATE_FORMAT(upday, '%Y-%m') as ym from event_news join t_event_news_site_type on event_news.id = t_event_news_site_type.event_news_id where t_event_news_site_type.site_type = 1 group by event_news.upday order by event_news.upday ASC [nativecode=2006 ** MySQL server has gone away]DB Error: no database selected