Home >Database >Mysql Tutorial >SQL语句中SUM与COUNT的区别深入分析_MySQL
SQL语句中SUM与COUNT的区别深入分析_MySQL
- WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOriginal
- 2016-06-01 13:24:34884browse
bitsCN.com
SUM是对符合条件的记录的数值列求和
COUNT 是对查询中符合条件的结果(或记录)的个数
例如：
表fruit
id name price
1 apple 3.00
2 pear 4.00
select count(price) from fruit; ----执行之后结果为：2 (表示有2条记录)
select sum(price) from fruit;---执行之后结果为：7:00（表示各记录price字段之和为7.00）
bitsCN.com
Statement：
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Previous article：深入mysql创建自定义函数与存储过程的详解_MySQLNext article：MySQL查询优化之explain的深入解析_MySQL