方法一：使用order by 进行排序并用limit 2,1选中倒数第三的员工信息
代码： select * from employees order by hire_date desc limit 2,1

方法二：运用子查询，可以处理当有多个员工在同一天入职的情形
代码： select * from employees where hire_date = (select distinct hire_date from employees order by hire_date desc limit 2,1)