MySQL的时间差函数(TIMESTAMPDIFF、DATEDIFF)、日期转换计算函数(date_add、day、date_format、str_to_dat

1. 时间差函数(TIMESTAMPDIFF、DATEDIFF) 需要用MySQL计算时间差,使用TIMESTAMPDIFF、DATEDIFF,记录一下实验结果 --0 select datediff(now(), now()); --2 select datediff('2015-04-22 23:59:00', '2015-04-20 00:00:00'); --2 select datediff('2015-04-22 00:00:00', '2015-04-20 23:59:00'); --1 select TIMESTAMPDIFF(DAY, '2015-04-20 23:59: