题解 | 获取当前薪水第二多的员工的emp_no以及其对应的薪水salary

WITH 
  T1 AS (
	  SELECT 
	  max(salary) maxsalary
	  FROM salaries
  ),
  T2 AS (
	  SELECT
	  max(salary) secondsalary
	  FROM salaries
	  WHERE salary < (SELECT maxsalary FROM T1)
)
SELECT 
  e.emp_no,
  salary,
  last_name,
  first_name
FROM 
	employees e 
	JOIN salaries s USING(emp_no)
WHERE 
	salary = (SELECT secondsalary FROM T2)