Calculate the time difference function Timestampdiff usage of two dates in MySQL

MySQL calculates the two-date time difference function Timestampdiff usage:
Grammar:
Timestampdiff (INTERVAL,DATETIME_EXPR1,DATETIME_EXPR2)
Description
Returns an integer difference between a date or datetime expression Datetime_expr1 and datetime_expr2the. The unit of the result is given by the interval parameter. The legal values for interval are the same as those listed in the Timestampadd () function description.

Mysql> SELECT Timestampdiff (MONTH, ' 2009-12-01 ', ' 2009-09-01 ');
-3
Mysql> SELECT Timestampdiff (year, ' 2009-05-01 ', ' 2008-01-01 ');

-1

Accurate to seconds difference

Select Timestampdiff (Second,date_format (now (), '%y-%m-%d%h:%i:%s '), ' 2013-03-07 15:43:00 ')
From dual

Calculate the time difference function Timestampdiff usage of two dates in MySQL