高斯数据库查询两个日期之间的天数

--设置时区信息，获取时间于本地电脑时间一致
SET TIME ZONE 'Asia/Shanghai';
--如果是为了获取天数，两日期使用减号计算，可以获得纯天数select
age('2021-01-01'::timestamp , '2018-01-01 18:27:00'::timestamp) as ageinfo,
extract(day from age('2021-01-01'::timestamp , '2018-01-01 18:27:00'::timestamp)) as days,
('2021-01-01'::timestamp - '1998-01-01 18:27:00'::timestamp) as realinfo,
extract(day from ('2021-01-01'::timestamp - '1998-01-01 18:27:00'::timestamp)) as realdays;