1.日期和时间间字段
date:日期字段，格式:2016-04-15
timestamp:时间字段，格式:2016-04-15 20:00:00
2.获取当时时间函数
postgres=# select now();
now
-------------------------------
2016-05-03 17:06:16.334648+08
postgres=# select current_timestamp;
now
-------------------------------
2016-05-03 17:12:30.403614+08
postgres=# select CURRENT_TIME;
timetz
------------------
17:21:20.1946+08
postgres=# select LOCALTIME;
time
-----------------
17:22:15.856583
postgres=# select LOCALTIMESTAMP;
timestamp
----------------------------
2016-05-03 17:22:27.235583
3.获取当天日期
postgres=# select current_date;
date
------------
2016-05-03
4.日期计算：
--使用interval
postgres=# select now()+interval '2 day';
?column?
-------------------------------
2016-05-05 17:26:07.931652+08
postgres=# select now()-interval '2 day';
?column?
-------------------------------
2016-05-01 17:26:43.908585+08
postgres=# select now()+interval '2 hour';
?column?
-------------------------------
2016-05-03 19:26:52.005566+08
5.时间截取
postgres=# select extract(year from now());
date_part
-----------
2016
postgres=# select extract(mon from now());
date_part
-----------
5
6.时间转换
postgres=# select timestamp '2012-05-12 18:54:54';
timestamp
---------------------
2012-05-12 18:54:54
postgres=# select date '2012-05-12 18:54:54';
date
------------
2012-05-12
postgres=# select date '2012-05-12 18:54:54';
date
------------
2012-05-12
postgres=# select TIMESTAMP WITH TIME ZONE '2012-05-12 18:54:54' ;
timestamptz
------------------------
2012-05-12 18:54:54+08
7.与unix时间戳的转换
postgres=# SELECT TIMESTAMP 'epoch' + 1341174767 * INTERVAL '1 second';
?column?
---------------------
2012-07-01 20:32:47
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版权声明：本文为CSDN博主「wxc20062006」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/wxc20062006/article/details/51306101
