题解
查询职位发布时间在2021年后或职位城市为上海的job_id, boss_id, company_id
https://www.nowcoder.com/practice/8beaed9f153d4f65acda4db12ae55ddd
将去重后的两个连接表作为一个临时表t，然后再进行排序
select job_id,boss_id,company_id from
(select job_id,boss_id,company_id,job_city from job_info where post_time > "2021-01-01"
union
select job_id,boss_id,company_id,job_city from job_info where job_city = "上海") t
order by t.job_city;
