sql不用order by查找第二的思路

主要思想为多层SELECT嵌套与MAX()函数结合 1、先利用MAX()函数找出salaries中当前薪水最高者，即SELECT MAX(salary) FROM salaries WHERE to_date = ‘9999-01-01‘ 2、再利用INNER JOIN连接employees与salaries表，限定条件为【同一员工】e.emp_no = s.emp_no、【当前】s.to_date = ‘9999-01-01‘与【非薪水最高】s.salary NOT IN (SELECT MAX(salary) FROM salaries WHERE to_date = ‘9999-01-01‘) 3、在以上限制条件下找薪水最高者，即为所有员工薪水的次高者   SELECT e.emp_no, MAX(s.salary) AS salary, e.last_name, e.first_name  FROM employees AS e INNER JOIN salaries AS s  ON e.emp_no = s.emp_no WHERE s.to_date = ‘9999-01-01‘ AND s.salary NOT IN (SELECT MAX(salary) FROM salaries WHERE to_date = ‘9999-01-01‘)  

方法二:

利用max选出最大，用where 限定小于最大值的，然后再取最大的那个

select a.emp_no,max(b.salary),a.last_name,a.first_name 

from employees a inner join salaries b

on a.emp_no=b.emp_no

where b.salary<(select max(salary) from salaries)

and b.to_date = ‘9999-01-01‘

 

sql不用order by查找第二的思路

标签：使用   join   log   color   date   rom   tab   最大值   key