select a.activities_id ,a.activities_name , a.need_people ,from_unixtime(a.activities_time,"%Y-%m-%d") as activities_time,
concat("http://www.aibeike.com/",ai.activities_url ) as activities_url,
(select count(*) from activities_apply where apply_state =3 and activities_id=a.activities_id)
as num from activities as a left join activities_img as ai on a.activities_id = ai.activities_id where a.group_id=1 order by a.add_time desc
