how to select max value from a subquery in SQL?-CodePudding

How come this SQL query doesn't work?

select max(t.salary) as salary from
(SELECT department_id "department Id", SUM(salary) "salary"  FROM EMPLOYEES GROUP BY department_id) t;

It shows "salary is invalid identifier " error

CodePudding user response：

SELECT SUM(salary) AS salary  
FROM EMPLOYEES 
GROUP BY department_id
ORDER BY salary DESC LIMIT 1;

CodePudding user response：

select max(t.salary) as salary 
from(
    SELECT department_id AS `department Id`, SUM(salary) AS `salary`
    FROM EMPLOYEES
    GROUP BY department_id
) AS t