Postgres 的 DATEADD 替代品
SELECT CURRENT_DATE + '1 day'::INTERVAL
SELECT '1999-12-11'::TIMESTAMP + '19 days'::INTERVAL
SELECT '1 month'::INTERVAL + '1 month 3 days'::INTERVAL
SELECT CURRENT_DATE + '1 day'::INTERVAL
SELECT '1999-12-11'::TIMESTAMP + '19 days'::INTERVAL
SELECT '1 month'::INTERVAL + '1 month 3 days'::INTERVAL