MySQL错误信息：sub select detect
错误信息：SELECT COUNT(*) as pcount,add_time FROM ( SELECT distinct ip,date(add_time) as add_time FROM `tongji` ) a group by add_time ORDER BY add_time desc LIMIT 7,sub select detect
错误信息：SELECT COUNT(*) as pcount,add_time FROM ( SELECT distinct ip,date(add_time) as add_time FROM `tongji` ) a group by add_time ORDER BY add_time desc LIMIT 7,sub select detect
