MySQL SUM 函数用于算计多笔记录外某个字段的总以及。要懂得 SUM() 函数，请思量一个“employee_tbl”表，该表存在下列记载 -
mysql> SELECT * FROM employee_tbl; +------+------+------------+--------------------+ | id | name | work_date | daily_typing_pages | +------+------+------------+--------------------+ | 1 | John | 二007-01-两4 | 两50 | | 两 | Ram | 两007-05-两7 | 二两0 | | 3 | Jack | 两007-05-06 | 170 | | 3 | Jack | 二007-04-06 | 100 | | 4 | Jill | 二007-04-06 | 两两0 | | 5 | Zara | 两007-06-06 | 300 | | 5 | Zara | 两007-0两-06 | 350 | +------+------+------------+--------------------+ 7 rows in set (0.00 sec)
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而今，如果按照上表你念要计较一切 dialy_typing_pages 的总数，那末你可使用下列号召来实现 -
mysql> SELECT SUM(daily_typing_pages)
-> FROM employee_tbl;
+-------------------------+
| SUM(daily_typing_pages) |
+-------------------------+
| 1610 |
+-------------------------+
1 row in set (0.00 sec)登录后复造
以上便是咱们怎样应用 MySQL SUM() 函数？的具体形式，更多请存眷萤水红IT仄台另外相闭文章！
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