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sql常用函数

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Jun 07, 2016 pm 05:46 PM

countfirstformatminsql

数据库有许多内置的职能履行的计算数据。

聚合函数的SQL
总的SQL函数返回一个单一的价值计算，从价值的一栏。

标功能的SQL
的SQL标量函数返回一个单一的价值，根据输入值。

有用标职能：

UCASE （） -转换领域的大写
LCASE （） -转换一个外地来小写
min（） -提取字符的文本字段
len（） -返回的长度文本字段
ROUND（） -查房一个数字领域的一些具体小数
NOW（） -返回当前系统日期和时间
format（） -格式如何领域显示
提示：总的职能和职责的量将详细解释在未来的章节。

有用的聚合函数：

AVG （） -返回的平均价值
count（） -返回的行数
first（） -返回第一个值
last（） -返回最后一个值
max（） -返回的最大价值
min（） -返回最小的价值
total（） -返回的总和

上面了sql函数都是我们常用到的,特别是给各位新手有很大的帮助哦,

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