1. MySQL
SELECT NOW();
eg: 2021-02-08 14:21:10
SELECT CURRENT_TIMESTAMP();
eg: 2021-02-08 14:21:10
SELECT SYSDATE();
eg: 2021-02-08 14:21:10
SELECT FROM_UNIXTIME(unix_timestamp())
eg: 2021-02-08 16:43:53
SELECT FROM_UNIXTIME(unix_timestamp(),'%Y-%m-%d %h:%m:%s');
eg: 2021-02-08 04:02:47
SELECT CURRENT_DATE();
eg: 2021-02-08
SELECT CURDATE();
eg: 2021-02-08
SELECT FROM_UNIXTIME(unix_timestamp(),'%Y-%m-%d');
eg: 2021-02-08
SELECT DATE_FORMAT(NOW(),'%Y-%m-%d');
eg: 2021-02-08
SELECT CURRENT_TIME();
eg: 17:06:22
SELECT FROM_UNIXTIME(2012424121,'%Y-%m-%d');
eg: 2033-10-09 (注意第一个参数是时间戳,第二个参数时格式)
SELECT DATE_FORMAT('2020/02/02','%Y-%m-%d');
eg: 2020-02-02(第一个参数为日期格式字符串,第二个参数是转化之后的日期格式)
SELECT STR_TO_DATE('2020-02-02 08:00:03','%Y-%m-%d %h:%m:%s');
eg: 2020-00-02 08:00:03(同上)
SELECT STR_TO_DATE('2020年02月02日','%Y年%m月%d日');
eg: 2020-02-02(第一个参数为日期格式字符串,第二个参数是当前给定日期的格式)
SELECT DATE_SUB(NOW(),INTERVAL 1 DAY);
SELECT DATE_ADD(NOW(),INTERVAL -1 DAY);
SELECT ADDDATE(NOW(),INTERVAL -1 DAY);
SELECT DATE_SUB(NOW(),INTERVAL -1 DAY);
SELECT DATE_ADD(NOW(),INTERVAL 1 DAY);
SELECT ADDDATE(NOW(),INTERVAL 1 DAY);
2. Hive
SELECT current_date();
eg: 2021-02-08
SELECT current_timestamp();
eg: 2021-02-08 14:24:59.764
SELECT unix_timestamp();
eg: 1612765707
SELECT from_unixtime(unix_timestamp(),'yyyy-MM-dd HH:dd:ss');
eg: 2021-02-08 14:08:59
SELECT from_unixtime(unix_timestamp(),'yyyy-MM-dd');
eg: 2021-02-08
SELECT date_add(from_unixtime(unix_timestamp(),'yyyy-MM-dd'),1);
SELECT date_sub(from_unixtime(unix_timestamp(),'yyyy-MM-dd'),-1);
SELECT date_add(from_unixtime(unix_timestamp(),'yyyy-MM-dd'),-1);
SELECT date_sub(from_unixtime(unix_timestamp(),'yyyy-MM-dd'),1);