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

keyword DATEDIFF