From: Tom Lane <tgl@sss.pgh.pa.us>
To: Bret Hughes <bhughes@elevating.com>
Cc: postgresql sql list <pgsql-sql@postgresql.org>
Subject: Re: definative way to place secs from epoc into timestamp column
Date: Wed, 02 Mar 2005 14:52:06 -0500
Message-ID: <13089.1109793126@sss.pgh.pa.us> (raw)
In-Reply-To: <1109780719.28180.86.camel@bretsony>
References: <1109780719.28180.86.camel@bretsony>
Bret Hughes <bhughes@elevating.com> writes:
> I give up. I have STFW and STFM and still do not feel like I have a
> good way to update/insert into a timestamp w/o TZ column with an integer
> representing seconds from epoch.
The docs say:
Here is how you can convert an epoch value back to a time stamp:
SELECT TIMESTAMP WITH TIME ZONE 'epoch' + 982384720 * INTERVAL '1 second';
If you want a timestamp w/o time zone then the right thing depends on
what you think the reference epoch is. If you do
SELECT TIMESTAMP WITHOUT TIME ZONE 'epoch' + 982384720 * INTERVAL '1 second';
then what you will get is the correct equivalent of the Unix timestamp
in GMT time. If you do the first calculation and then cast to timestamp
w/o time zone then what you will get is a correct equivalent in your
TimeZone setting. For instance
regression=# show timezone;
TimeZone
----------
EST5EDT
(1 row)
regression=# SELECT TIMESTAMP WITH TIME ZONE 'epoch' + 982384720 * INTERVAL '1 second';
?column?
------------------------
2001-02-16 23:38:40-05
(1 row)
regression=# SELECT TIMESTAMP WITHOUT TIME ZONE 'epoch' + 982384720 * INTERVAL '1 second';
?column?
---------------------
2001-02-17 04:38:40
(1 row)
regression=# SELECT (TIMESTAMP WITH TIME ZONE 'epoch' + 982384720 * INTERVAL '1 second')::timestamp without time zone;
timestamp
---------------------
2001-02-16 23:38:40
(1 row)
regards, tom lane
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To: pgsql-sql@postgresql.org
Cc: tgl@sss.pgh.pa.us, bhughes@elevating.com
Subject: Re: definative way to place secs from epoc into timestamp column
In-Reply-To: <13089.1109793126@sss.pgh.pa.us>
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