MYSQL必知必会读书笔记第十和十一章之使用函数处理数据_MySQL
代码如下:
select avg(prod_price) as avg_pricefrom products;
- 计数
使用count(*)对表中行的数目进行计数（whether null or not）
使用count(column)对特定列具有值的行进行计数，忽略null
求和
使用sum()返回指定列值的和
以上所述是小编给大家介绍的MYSQL必知必会读书笔记第十和十一章之使用函数处理数据的相关知识，希望对大家有所帮助！
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