了悟生死大事

select need.*,(case user_class_id when '3' then (select real_name from bussiness_person_info where need.username=bussiness_person_info.username) else (select simple_name from bussiness_enterprise_info where need.username=bussiness_enterprise_info.username.

如果ps -ef | grep ngnix 后，在kill -QUIT process_id杀不死。 就用fuser -n tcp 80 ，查看那个进程运行，然后选第一个kill。