DATEDIFF

描述

计算给定日期之间的差值。

语法

DATEDIFF(<expr1>, <expr2>)

参数

参数	说明
<expr1>	日期被减数
<expr2>	日期减数

返回值

返回 expr1 - expr2 的值，结果精确到天。

举例

select datediff(CAST('2007-12-31 23:59:59' AS DATETIME), CAST('2007-12-30' AS DATETIME));

+-----------------------------------------------------------------------------------+
| datediff(CAST('2007-12-31 23:59:59' AS DATETIME), CAST('2007-12-30' AS DATETIME)) |
+-----------------------------------------------------------------------------------+
|                                                                                 1 |
+-----------------------------------------------------------------------------------+

select datediff(CAST('2010-11-30 23:59:59' AS DATETIME), CAST('2010-12-31' AS DATETIME));

+-----------------------------------------------------------------------------------+
| datediff(CAST('2010-11-30 23:59:59' AS DATETIME), CAST('2010-12-31' AS DATETIME)) |
+-----------------------------------------------------------------------------------+
|                                                                               -31 |
+-----------------------------------------------------------------------------------+