Re: BUG #7824: documentation bug: Extract DOW

On Tue, Jan 22, 2013 at 08:40:30PM +0000, tim(dot)romano(at)yahoo(dot)com wrote:
> The following bug has been logged on the website:
>
> Bug reference: 7824
> Logged by: Tim Romano
> Email address: tim(dot)romano(at)yahoo(dot)com
> PostgreSQL version: 9.2.2
> Operating system: Windows 7 x64
> Description:
>
> Documentation seems to indicate that only a Timestamp value is a valid
> argument to the Extract function when trying to get the DOW, but a Date also
> works:
>
> dow
> The day of the week (0 - 6; Sunday is 0) (for timestamp values only)
>
> SELECT EXTRACT(DOW FROM TIMESTAMP '2001-02-16 20:38:40'); Result: 5

[Sorry for the late reply.]

I assume you mean:

SELECT EXTRACT(DOW FROM DATE '2001-02-16');
date_part
-----------
5
(1 row)

That does work fine, and is documented in PG 9.2:

http://www.postgresql.org/docs/9.2/static/functions-datetime.html#FUNCTIONS-DATETIME-EXTRACT
The extract function retrieves subfields such as year or hour from
date/time values. source must be a value expression of type timestamp,
--> time, or interval. (Expressions of type date are cast to timestamp and
--> can therefore be used as well.)

Where did you see that DATE is not supported for EXTRACT?

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +