查询总工资最多的部门，显示部门编号，部门名
select d.department_id, d.department_name from hr.departments d where d.department_id=(
	select e.department_id from hr.employees e group by e.department_id having sum(e.salary)=(
		select max(sum(salary)) from hr.employees e group by e.department_id     
	)
)

select * from 
(
  select sum_salary, e.department_id, d.department_name from
        (
            select sum(salary) sum_salary , department_id from employees group by department_id
        ) e 
        left join departments d on e.department_id = d.department_id order by sum_salary desc
) 
where rownum = 1

select e.* from where hr.employees where e.department_id=
(select d.department_id from hr.departments d where e.location_id=
        (select l.location_id from hr.locations l where l.state_province='SouthSan Francisco'
         )
)

select * from(
       select sum(tmp1.salary) as total_salary, tmp1.department_id, tmp1.department_name from (
              select e.*,d.department_name from hr.employees e left join hr.departments d on e.department_id = d.department_id
              )tmp1 group by tmp1.department_id, tmp1.department_name order by total_salary desc
              )tmp2 where  tmp2.total_salary = (
                                               select max(total_salary) from (
                                              select sum(tmp3.salary) as total_salary, tmp3.department_id, tmp3.department_name from (
                                              select e.*,d.department_name from hr.employees e left join hr.departments d on e.department_id = d.department_id
                                              )tmp3 group by tmp3.department_id, tmp3.department_name order by total_salary desc
                                             ))