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
SELECT job_id, boss_id, company_id FROM ( SELECT job_id, boss_id, company_id, job_city FROM job_info WHERE job_city = '上海' UNION SELECT job_id, boss_id, company_id, job_city FROM job_info WHERE YEAR(post_time) >= 2021 ) AS t ORDER BY job_city