datediff

description

Syntax

DATETIME DATEDIFF(DATETIME expr1,DATETIME expr2)

计算expr1 - expr2，结果精确到天。

expr1 和 expr2 参数是合法的日期或日期/时间表达式。

注释：只有值的日期部分参与计算。

example

1. mysql> select datediff(CAST('2007-12-31 23:59:59' AS DATETIME), CAST('2007-12-30' AS DATETIME));
2. +-----------------------------------------------------------------------------------+
3. | datediff(CAST('2007-12-31 23:59:59' AS DATETIME), CAST('2007-12-30' AS DATETIME)) |
4. +-----------------------------------------------------------------------------------+
5. |                                                                                 1 |
6. +-----------------------------------------------------------------------------------+

8. mysql> select datediff(CAST('2010-11-30 23:59:59' AS DATETIME), CAST('2010-12-31' AS DATETIME));
9. +-----------------------------------------------------------------------------------+
10. | datediff(CAST('2010-11-30 23:59:59' AS DATETIME), CAST('2010-12-31' AS DATETIME)) |
11. +-----------------------------------------------------------------------------------+
12. |                                                                               -31 |
13. +-----------------------------------------------------------------------------------+

keyword

DATEDIFF