与另一行聚合函数分组

Question

我正在尝试从部门列中获取最高薪水，但我也想认识那个部门的人

我可以在这里做什么？

create table if not exists employee(
    id serial unique,
    firstName varchar (15),
    lastName varchar(15),
    department varchar (20),
    salary int
);

select department, max(salary) from employee
group by department

Answer 1

计算按薪水降序排序的排名。
前1名将获得第1名。

select department, salary, firstName, lastName
from
(
    select department, salary, firstName, lastName
    , dense_rank() over (partition by department order by salary desc) as Rnk
    from employee 
) q
where Rnk = 1

Answer 2

PostgreSQL 有一个漂亮的 distinct on 语法，您可以使用：

SELECT   DISTINCT ON (department) * 
FROM     employee
ORDER BY department ASC, salary DESC

SQLFiddle demo

与另一行聚合函数分组

group by with another row aggregate function

sql

postgresql

group-by

aggregate

postgresql-9.4