oracle学习68-oracle之数据处理之课后练习

55. 更改 108 员工的信息: 使其工资变为所在部门中的最高工资, job 变为公司中平均工资最低的 job
  1). 搭建骨架
  update employees 
  set salary = (
  ), job_id = (
  ) where employee_id = 108;
  2). 所在部门中的最高工资  
  select max(salary)
  from employees
  where department_id = (
    select department_id
    from employees
    where employee_id = 108
  )
  3). 公司中平均工资最低的 job
  select job_id
  from employees
  group by job_id
  having avg(salary) =  (
    select min(avg(salary))
    from employees
    group by job_id
  )
  4). 填充
  update employees e set salary = (
    select max(salary)
    from employees
    where department_id = e.department_id
  ), job_id = (
    select job_id
    from employees
    group by job_id
    having avg(salary) =  (
      select min(avg(salary))
      from employees
      group by job_id
    )
  ) where employee_id = 108;
56. 删除 108 号员工所在部门中工资最低的那个员工.
  1). 查询 108 员工所在的部门 id
  select department_id
  from employees 
  where employee_id = 108;
  2). 查询 1) 部门中的最低工资:
  select min(salary)
  from employees
  where department_id = (
    select department_id
    from employees 
    where employee_id = 108
  )
  3). 删除 1) 部门中工资为 2) 的员工信息:
  delete from employees e
    where department_id = (
            select department_id
            from employees e
            where employee_id = 108
    ) and salary = (
            select min(salary)
            from employees
            where department_id = e.department_id
    )