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# timestampdiff
## description
### Syntax

`INT TIMESTAMPDIFF(unit,DATETIME datetime_expr1, DATETIME datetime_expr2)`

返回datetime_expr2−datetime_expr1，其中datetime_expr1和datetime_expr2是日期或日期时间表达式。

结果(整数)的单位由unit参数给出。interval的单位由unit参数给出，它应该是下列值之一: 
                   
SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, or YEAR。

## example

```

MySQL> SELECT TIMESTAMPDIFF(MONTH,'2003-02-01','2003-05-01');
+--------------------------------------------------------------------+
| timestampdiff(MONTH, '2003-02-01 00:00:00', '2003-05-01 00:00:00') |
+--------------------------------------------------------------------+
|                                                                  3 |
+--------------------------------------------------------------------+

MySQL> SELECT TIMESTAMPDIFF(YEAR,'2002-05-01','2001-01-01');
+-------------------------------------------------------------------+
| timestampdiff(YEAR, '2002-05-01 00:00:00', '2001-01-01 00:00:00') |
+-------------------------------------------------------------------+
|                                                                -1 |
+-------------------------------------------------------------------+


MySQL> SELECT TIMESTAMPDIFF(MINUTE,'2003-02-01','2003-05-01 12:05:55');
+---------------------------------------------------------------------+
| timestampdiff(MINUTE, '2003-02-01 00:00:00', '2003-05-01 12:05:55') |
+---------------------------------------------------------------------+
|                                                              128885 |
+---------------------------------------------------------------------+

```
##keyword
TIMESTAMPDIFF