176.第二高的薪水

Question

select salary 
from employee
order by salary desc limit 2 
having salary <> max(salary)

select salary 
from employee 
order by salary desc limit 1 
having salary not in (select max(salary) from employee);

上述查询无效并给出响应

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'having salary <> max(salary)' at line 2

由于 having 用于聚合器功能，因此在我看来这应该可行。

请帮助我解释为什么它不起作用我也在努力学习SQL查询如果可能请为我提供资源。

Answer 1

我们要第二高的薪水。

<!-- -->
>     create table employee (salary int);
>     insert into employee values (1),(2),(3),(4),(5),(6),(7),(8);
> 
> <pre>
> ✓
> 
> ✓
> </pre>

<!-- -->
>       select salary 
>       from employee 
>       order by salary desc 
>       limit 1, 1 ;
> 
> <pre>
> | salary |
> | -----: |
> |      7 |
> </pre>

*db<>fiddle [here](https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=ddf303748ee5620b2334b95621024840)*

Answer 2

另一个选项是使用 window 函数：

WITH cte AS
(
SELECT *,
   DENSE_RANK() OVER (ORDER BY salary Desc) AS Rnk
FROM employee
)
SELECT cte.salary
FROM cte
WHERE Rnk=2;

请注意，如果您有薪水 5000, 5000, 3000 ，正如@Thorsten Kettner 在评论中提到的那样，第二高的薪水将是 3000。

https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=90c67881bcf6fd8f0c50a5a351f6b9ca

176.第二高的薪水

176. Second Highest Salary

mysql

sql