SELECTMAX(salary)ASmax_salary,e.`department_id` didFROMemployees eGROUPBYe.`department_id` 结果为: 再将此表命名tmp在进行查询 SELECTMIN(max_salary),didFROM(SELECTMAX(salary)ASmax_salary,e.`department_id` didFROMemployees eGROUPBYe.`department_id`)AStmp 此时结果却为: 由此可见查询之后的表结构...