mysql - 缩短嵌套 SQL 查询

Question

列出工资高于给定员工所在部门平均工资的员工姓名。

我提出了以下解决方案: 名为employee的表中的列名是:emp_id、name、dept、salary。

select name from employee
where salary >
(
select avg(salary) from employee
where dept= (select dept from employee where emp_id = 'a10')
) 
and
dept = (select dept from employee where emp_id = 'a10')
;

我可以将这个查询缩短一点，并期望得到相同的结果吗？

Answer 1

这个查询是特定于 Oracle 的，但它的优点是只访问 employee 表一次:

select name from 
   (select name, 
           salary, 
           avg(salary) over (partition by dept) as avg_salary 
      from employee)
where salary > avg_salary;