SQL 求和()
SQL SUM() 函數
#SUM() 函數
SUM() 函數傳回數值列的總數。
SQL SUM() 語法
SELECT SUM(column_name) FROM table_name;
示範資料庫
在本教學中，我們將使用php 樣本資料庫。
下面是選自"access_log" 表的資料：
mysql> SELECT * FROM access_log;
+-----+------- --+-------+------------+
| aid | site_id | count | date |
+-----+---- -----+-------+------------+
| 1 | 1 | 45 | 2016-05-10 |#1 | 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)
+-----+------- --+-------+------------+
| aid | site_id | count | date |
+-----+---- -----+-------+------------+
| 1 | 1 | 45 | 2016-05-10 |#1 | 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 語句尋找"access_log" 表的"count" 欄位的總數：
實例#
SELECT SUM(count) AS nums FROM access_log;執行上述 SQL 輸出結果如下：
##
