Date: Thu, 17 Sep 2009 12:39:59 -0500
From: Kenneth Marshall <ktm@rice.edu>
To: Gavin McCullagh <gavin.mccullagh@gcd.ie>
Cc: pgsql-sql@postgresql.org
Subject: Re: extracting from epoch values in pgsql
Message-ID: <20090917173959.GE22802@it.is.rice.edu>
References: <20090917164439.GU16815@gcd.ie> <4AB26B6F.4010207@sympatico.ca>
	<20090917173039.GV16815@gcd.ie> <20090917173439.GW16815@gcd.ie>
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On Thu, Sep 17, 2009 at 06:34:39PM +0100, Gavin McCullagh wrote:
> On Thu, 17 Sep 2009, Gavin McCullagh wrote:
> 
> > On Thu, 17 Sep 2009, Frank Bax wrote:
> > 
> > > Gavin McCullagh wrote:
> > >> SELECT time, to_timestamp(time) AS ts, 
> > >> EXTRACT('months',to_timestamp(time)) FROM mdl_log;
> > >> ERROR:  syntax error at or near ","
> > >> LINE 1: ...t time, to_timestamp(time) AS ts, extract('months',to_times...
> > >
> > > Try replacing extract('month',value) with extract('months' from value)
> > 
> > Makes no difference whether month or months:
> 
> Actually, I pasted a different query, but based on the one in my last
> email:
> 
> moodle-01-01-2009=# SELECT EXTRACT('months',(TIMESTAMP WITH TIME ZONE 'epoch' + mdl_log.time * INTERVAL '1 second'))
> FROM mdl_log;
> ERROR:  syntax error at or near ","
> LINE 1: SELECT EXTRACT('months',(TIMESTAMP WITH TIME ZONE 'epoch' + ...
>                                ^
> moodle-01-01-2009=# SELECT EXTRACT('month',(TIMESTAMP WITH TIME ZONE 'epoch' + mdl_log.time * INTERVAL '1 second'))
> FROM mdl_log;
> ERROR:  syntax error at or near ","
> LINE 1: SELECT EXTRACT('month',(TIMESTAMP WITH TIME ZONE 'epoch' + m...
>                               ^
> 
> Gavin
> 
Gavin,

I think Frank had the answer:

Try replacing extract('month',value) with extract('months' from value)

Look at the documentation for the syntax for further details.

Regards,
Ken