Обсуждение: how to convert a time interval to seconds?

Hi,

I searched how to convert a time interval to seconds but failed to find
an example.

I want to convert the following wait_time column into seconds. How can I
do that? The datatype for the wait_time is time without timezone.

 job_number | task_number |   submission_time   | wait_time
------------+-------------+---------------------+-----------
         56 |           0 | 2006-04-13 08:47:53 | 00:01:28
         55 |           0 | 2006-04-13 08:47:51 | 00:01:21
         58 |           0 | 2006-04-13 08:47:54 | 00:01:28
         60 |           0 | 2006-04-13 08:47:55 | 00:01:27

Thanks,

- Chansup

On Tue, Sep 12, 2006 at 10:39:25AM -0400, Chansup Byun wrote:
> I searched how to convert a time interval to seconds but failed to find
> an example.

Searching the list archives for "interval to seconds" returns many
examples.  See also "Date/Time Functions and Operators" in the
documentation.

http://archives.postgresql.org/
http://www.postgresql.org/docs/8.1/interactive/functions-datetime.html

EXTRACT(EPOCH FROM interval_value)

> I want to convert the following wait_time column into seconds. How can I
> do that? The datatype for the wait_time is time without timezone.
>
>  job_number | task_number |   submission_time   | wait_time
> ------------+-------------+---------------------+-----------
>          56 |           0 | 2006-04-13 08:47:53 | 00:01:28

Does wait_time represent a duration?  If so then why is it a time
without timezone instead of an interval?

--
Michael Fuhr

am  Tue, dem 12.09.2006, um 10:39:25 -0400 mailte Chansup Byun folgendes:
> Hi,
>
> I searched how to convert a time interval to seconds but failed to find
> an example.

select extract('epoch' from timestamp);

A little example:

test=*> select '5 days 5 hours'::interval;
    interval
-----------------
 5 days 05:00:00
(1 row)

test=*> select extract ('epoch' from '5 days 5 hours'::interval);
 date_part
-----------
    450000
(1 row)



http://www.postgresql.org/docs/8.1/interactive/functions-datetime.html#FUNCTIONS-DATETIME-EXTRACT

HTH, Andreas
--
Andreas Kretschmer
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