题解 | 开窗函数yyds

with temp as(select 
    s.emp_no a,
    dept_no b,
    s.from_date,
    salary,
    max(salary) over(partition by dept_no order by s.from_date rows between unbounded preceding and unbounded following) c
from dept_emp d join salaries s on d.emp_no = s.emp_no)
select b,a,salary
from temp where salary = c