SQL SUM() 函數
SUM() 函數
SUM() 函數返回數值列的總數。
SQL SUM() 語法
SELECT SUM(column_name) FROM table_name;
演示數據庫
在本教程中,我們將使用w3big 樣本數據庫。
下面是選自"access_log" 表的數據:
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() 實例
下面的SQL 語句查找"access_log" 表的"count" 字段的總數:
實例
SELECT SUM(count) AS nums FROM access_log;
執行以上SQL 輸出結果如下: