sql两个指定日期相减

1.日期相减得天数

select to_date('2022-03-06','yyyy-mm-dd')-to_date('2022-03-03','yyyy-mm-dd') as today from dual

结果：3

2.日期减天数等于日期

select (to_date('2022-03-06','yyyy-mm-dd')-2) as time from dual

结果：2022/3/4