MySQL AVG方法用法及代碼示例

例子

返回學生的平均年齡：

SELECT AVG(age) AS "Average Age"
FROM students;



+-------------+
| Average Age |
+-------------+
|     17.4000 |
+-------------+
1 row in set (0.00 sec)

僅篩選年齡高於平均年齡的學生：

SELECT *
FROM students
WHERE age > (SELECT AVG(age) FROM students);



+------------+--------+-------+--------------+------+----------+
| student_id | fname  | lname | day_enrolled | age  | username |
+------------+--------+-------+--------------+------+----------+
|          2 | Ben    | Davis | 2016-04-20   |   19 | bdavis2  |
|          3 | Travis | Apple | 2018-08-14   |   18 | tapple3  |
+------------+--------+-------+--------------+------+----------+
2 rows in set (0.01 sec)