Re: extracting from epoch values in pgsql

2009/9/17 Gavin McCullagh <gavin(dot)mccullagh(at)gcd(dot)ie>:
> 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:
>
> moodle-01-01-2009=# select time, to_timestamp(time) AS ts, extract('month','to_timestamp(time)') from mdl_log LIMIT 10;
> ERROR:  syntax error at or near ","
> LINE 1: ...ct time, to_timestamp(time) AS ts, extract('month','to_times...
>                                                             ^
> moodle-01-01-2009=# select time, to_timestamp(time) AS ts, extract('months','to_timestamp(time)') from mdl_log LIMIT 10;
> ERROR:  syntax error at or near ","
> LINE 1: ...t time, to_timestamp(time) AS ts, extract('months','to_times...
>                                                             ^

>From manual:
http://www.postgresql.org/docs/current/interactive/functions-datetime.html

date_part('month',to_timestamp(time))
or
extract(month from to_timestamp(time))

Osvaldo