試題詳解

31有一員工資料表EMP，主鍵為emp_id，另外兩個屬性為員工薪水（salary)和所屬部門代碼（dept_id)， 下列何者可列出每個部門的最高薪水和該部門的代碼？
(A) SELECT MAX(salary) FROM EMP
(B) SELECT salary FROM EMP GROUP BY dept_id
(C)SELECT MAX(salary), dept_id FROM EMP GROUP BY dept_id
(D)SELECT MAX(salary), dept_id FROM EMP GROUP BY salary