资料库mySQL问题。出现1248问题。急修改

出现了#1248 - Every derived table must have its own alias ，请问如何修改
SELECt MIN(maximum_salary)
FROM (
SELECt dept_name, MAX(salary) maximum_salary
FROM instructor
GROUP BY dept_name
);

SELECt MIN(maximum_salary)
FROM (
SELECt dept_name, MAX(salary) maximum_salary
FROM instructor
GROUP BY dept_name
) TMP, 你必须给这个嵌套查询一个名字

虽然我很聪明，但这么说真的难到我了