1. 先用hire_date反排序(order by XXX desc),然后select all
select * from employees as latest
order by hire_date desc limit 1
  1. 使用select max()选出hire_date最大值,然后用where筛选出和最大值一样的hire_date,最后select all
select * from employees as latest
where latest.hire_date = (select max(hire_date) from employees)