题解 | where创建表p,p中剔除max,继续在p表中保留max,即第二max
select e.emp_no,salary,last_name,first_name from employees e join salaries s on e.emp_no=s.emp_no where salary= (select max(salary) from (select salary from employees e join salaries s on e.emp_no=s.emp_no where salary!=(select max(salary) from salaries)) p)