题解 | #按之字形顺序打印二叉树#
获取当前薪水第二多的员工的emp_no以及其对应的薪水salary
http://www.nowcoder.com/practice/c1472daba75d4635b7f8540b837cc719
select e.emp_no,s.salary,e.last_name,e.first_name from employees e join (select emp_no,salary from salaries where salary = (select MAX(salary) salary from salaries where salary != (select MAX(salary) from salaries))) s on e.emp_no = s.emp_no