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 job1). 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 employeeswhere department_id = (select department_idfrom employeeswhere employee_id = 108)3). 公司中平均工资最低的 jobselect job_idfrom employeesgroup by job_idhaving avg(salary) =  (select min(avg(salary))from employeesgroup by job_id)4). 填充update employees e set salary = (select max(salary)from employeeswhere department_id = e.department_id), job_id = (select job_idfrom employeesgroup by job_idhaving avg(salary) =  (select min(avg(salary))from employeesgroup 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 idselect department_idfrom employees where employee_id = 108;2). 查询 1) 部门中的最低工资:select min(salary)from employeeswhere department_id = (select department_idfrom employees where employee_id = 108)3). 删除 1) 部门中工资为 2) 的员工信息:delete from employees ewhere department_id = (select department_idfrom employees ewhere employee_id = 108) and salary = (select min(salary)from employeeswhere department_id = e.department_id)