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SQL SUM() 函数
SQL SUM() 函数SUM() 函数SUM() 函数返回数值列的总数。SQL SUM() 语法SELECT SUM(column_name) FROM table_name;演示数据库在本教程中,我们将使用 RUNOOB 样本数据库。下面是选自 "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 |+-----+---------+-------+------------+9 rows in set (0.00 sec)SQL SUM() 实例下面的 SQL 语句查找 "access_log" 表的 "count" 字段的总数:实例SELECT SUM(count) AS nums FROM access_log;执行以上 SQL 输出结果如下:
SQL SUM() 函数