1.日期和時間間字段
date:日期字段，格式:2016-04-15
timestamp:時間字段，格式:2016-04-15 20:00:00
2.獲取當時時間函數
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.獲取當天日期
postgres=# select current_date;
date
------------
2016-05-03
4.日期計算：
--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.時間截取
postgres=# select extract(year from now());
date_part
-----------
2016
postgres=# select extract(mon from now());
date_part
-----------
5
6.時間轉換
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.與unix時間戳的轉換
postgres=# SELECT TIMESTAMP 'epoch' + 1341174767 * INTERVAL '1 second';
?column?
---------------------
2012-07-01 20:32:47
————————————————
版權聲明：本文爲CSDN博主「wxc20062006」的原創文章，遵循 CC 4.0 BY-SA 版權協議，轉載請附上原文出處鏈接及本聲明。
原文鏈接：https://blog.csdn.net/wxc20062006/article/details/51306101