SUM() 函数

SUM() 函数

返回数值列的总数。

语法

SELECT SUM(column_name) FROM table_name;

示例

"access_log" 表的数据：

mysql> SELECT * FROM access_log;
+-----+---------+-------+------------+
| aid | site_id | count | date       |
+-----+---------+-------+------------+
|   1 |       1 |    45 | 2016-05-10 |
|   2 |       3 |   100 | 2016-05-13 |
|   3 |       1 |   230 | 2016-05-14 |
|   4 |       2 |    10 | 2016-05-14 |
|   5 |       5 |   205 | 2016-05-14 |
|   6 |       4 |    13 | 2016-05-15 |
|   7 |       3 |   220 | 2016-05-15 |
|   8 |       5 |   545 | 2016-05-16 |
|   9 |       3 |   201 | 2016-05-17 |
+-----+---------+-------+------------+

查找 "access_log" 表的 "count" 字段的总数：

SELECT SUM(count) AS nums FROM access_log;

输出结果：

mysql> SELECT SUM(count) AS nums FROM access_log;


+---------+
| nums    |
+---------+
| 1569    |
+---------+