select job_id,boss_id,company_id from ( select job_id,boss_id,company_id,job_city from job_info where year(post_time) >= '2021' union select job_id,boss_id,company_id,job_city from job_info where job_city = '上海' ) t order by job_city; 如果在union之后直接使用order by是会报错的,因为sele...