試題詳解

9. 資料表 Emp 之欄位屬性定義：Empid INTEGER、Name CHAR(20)、DeptnoINTEGER、Sal INTEGER；欲表列「部門代號 20 及 50 的員工平均薪資(Sal)在 22,000 元(含)以上」之部門代號(Deptno)，最能符合要求之 SQL 語法為何？
(A)SELECT Deptno, AVG(Sal) FROM Emp WHERE Deptno IN(20,50) GROUP BY Deptno HAVING AVG(Sal)>=22000
(B)SELECT Deptno,AVG(Sal) FROM Emp GROUP BY Deptno HAVING AVG(Sal)>=22000 ANDDeptno IN (20,50)
(C)SELECT Deptno, AVG(Sal) FROM Emp WHEREDeptno IN (20,50) AND AVG(Sal)>=22000 GROUP BY Deptno
(D)SELECTDeptno, AVG(Sal) FROM Emp WHERE Deptno IN (20,50) GROUP BYAVG(Sal) HAVING AVG(Sal)>=22000 。