--日期转时间戳
SELECT EXTRACT(epoch FROM NOW());
SELECT EXTRACT(epoch FROM CAST('2017-12-06' AS TIMESTAMP));
--时间戳转日期
SELECT TO_TIMESTAMP(1512490630);
--日期转时间戳
SELECT EXTRACT(epoch FROM NOW());
SELECT EXTRACT(epoch FROM CAST('2017-12-06' AS TIMESTAMP));
--时间戳转日期
SELECT TO_TIMESTAMP(1512490630);