MySQL计算天数差

1、TO_DAYS函数

  select to_days('2023-07-20') - to_days('2022-07-19') from test; // 结果366天

2、TIMESTAMPDIFF函数

select timestampdiff(param,datetime1,datetime2) from test; 

计算两日期时间之间相差的天数，秒数，分钟数，周数，小时数，param可以为FRAC_SECOND (microseconds), SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, YEAR，结果是datetime1 和datetime2之间的整数差

select timestampdiff(hour,'2022-07-10 10:20:20','2022-07-10 20:20:20')  from test; // 结果10小时

3、DATEDIFF函数

select datediff(‘2022-07-20’,'2020-06-20') from test;