Re: Problem with Day of Week
Re: Problem with Day of Week
От:
"Ross J. Reedstrom" <reedstrm@rice.edu>
Дата:
On Mon, Feb 05, 2001 at 05:15:47PM +0100, Karel Zak wrote:
>
> test=# select date_part('dow','2001-02-11'::timestamp);
> date_part
> -----------
> 0
>
> test=# select to_char('2001-02-11'::timestamp, 'D');
> to_char
> ---------
> 1
>
>
> date_part is based on zero - use range 0-6
> to_char is based on one - use range 1-7
>
My understanding is that one is ISO, the other is for Oracle
compatability, is that not right Karel?
Ross
Problem with Day of Week
От:
Keith Perry <keith@vcsn.com>
Дата:
Greetings,
I notice some talk about date problems and interestingly enough planning
out an application in which I will need to be able to manipulate dates.
I notice however that there seems to be a discrepancy with the day or
week in 7.0.3
---
pmhcc=# select date_part('dow','now'::timestamp);date_part
----------- 1
(1 row)
pmhcc=# select to_char('now'::timestamp,'D');to_char
---------2
(1 row)
pmhcc=# select version(); version
---------------------------------------------------------------------PostgreSQL 7.0.3 on i686-pc-linux-gnu, compiled by gcc egcs-2.91.66
(1 row)
pmhcc=# select now(); now
------------------------2001-01-29 12:57:46-05
(1 row)
---
Now as far as I know, Sunday is supposed to 1, so I would think that
date_part is doing something funky unless I am mis-understanding
something. I was hoping that someone might be able to shead some light
on this. Thanks.
Keith C. Perry
VCSN, Inc.
http://vcsn.com
Re: Problem with Day of Week
От:
"Brian C. Doyle" <bcdoyle@mindspring.com>
Дата:
Keith,
Try:
select to_char('now'::timestamp,'Dy'); to_char
--------- Mon
(1 row)
----------------------------------------------------------
DAY = full upper case day name (9 chars)
Day = full mixed case day name (9 chars)
day = full lower case day name (9 chars)
DY = abbreviated upper case day name (3 chars)
Dy = abbreviated mixed case day name (3 chars)
dy = abbreviated lower case day name (3 chars)
DDD = day of year (001-366)
DD = day of month (01-31)
D = day of week (1-7; SUN=1)
-------------------------------------------------------------
Taken from
http://www.postgresql.org/users-lounge/docs/7.0/user/functions2972.htm
At 12:55 PM 1/29/01 -0500, Keith Perry wrote:
>Greetings,
>
>I notice some talk about date problems and interestingly enough planning
>out an application in which I will need to be able to manipulate dates.
>I notice however that there seems to be a discrepancy with the day or
>week in 7.0.3
>
>---
>
>pmhcc=# select date_part('dow','now'::timestamp);
> date_part
>-----------
> 1
>(1 row)
>
>pmhcc=# select to_char('now'::timestamp,'D');
> to_char
>---------
> 2
>(1 row)
>
>pmhcc=# select version();
> version
>---------------------------------------------------------------------
> PostgreSQL 7.0.3 on i686-pc-linux-gnu, compiled by gcc egcs-2.91.66
>(1 row)
>
>pmhcc=# select now();
> now
>------------------------
> 2001-01-29 12:57:46-05
>(1 row)
>
>---
>
>Now as far as I know, Sunday is supposed to 1, so I would think that
>date_part is doing something funky unless I am mis-understanding
>something. I was hoping that someone might be able to shead some light
>on this. Thanks.
>
>Keith C. Perry
>VCSN, Inc.
>http://vcsn.com
Re: Problem with Day of Week
От:
Karel Zak <zakkr@zf.jcu.cz>
Дата:
On Mon, 29 Jan 2001, Keith Perry wrote:
> Greetings,
>
> I notice some talk about date problems and interestingly enough planning
> out an application in which I will need to be able to manipulate dates.
> I notice however that there seems to be a discrepancy with the day or
> week in 7.0.3
>
> ---
>
> pmhcc=# select date_part('dow','now'::timestamp);
> date_part
> -----------
> 1
> (1 row)
>
> pmhcc=# select to_char('now'::timestamp,'D');
> to_char
> ---------
> 2
> (1 row)
>
See:
test=# select date_part('dow','2001-02-11'::timestamp);date_part
----------- 0
test=# select to_char('2001-02-11'::timestamp, 'D');to_char
---------1date_part is based on zero - use range 0-6to_char is based on one - use range 1-7
Karel
Re: Problem with Day of Week
От:
Karel Zak <zakkr@zf.jcu.cz>
Дата:
On Mon, 5 Feb 2001, Ross J. Reedstrom wrote:
> On Mon, Feb 05, 2001 at 05:15:47PM +0100, Karel Zak wrote:
> >
> > test=# select date_part('dow','2001-02-11'::timestamp);
> > date_part
> > -----------
> > 0
> >
> > test=# select to_char('2001-02-11'::timestamp, 'D');
> > to_char
> > ---------
> > 1
> >
> >
> > date_part is based on zero - use range 0-6
> > to_char is based on one - use range 1-7
> >
>
> My understanding is that one is ISO, the other is for Oracle
> compatability, is that not right Karel?
You are right, Larry Ellison use 1-7 (he must, if the PostgreSQL to_char()
is 100% comapatible :-)
I don't know if 0-6 is like ISO (Thomas?), but surely it's like POSIX.
Karel
Re: Problem with Day of Week
От:
Karel Zak <zakkr@zf.jcu.cz>
Дата:
On Mon, 5 Feb 2001 keith@vcsn.com wrote: > Ok, so there is actually two standards then. Is this documented > anywhere? Is this is something that is going to change? I don't want > to write and app and have things "break" during and upgrade :) I mean you can be caseful. Not changes planned here. date_part() is not documented to much in detail, but formatting functions are described good. Karel
Re: Problem with Day of Week
От:
<keith@vcsn.com>
Дата:
Ok, so there is actually two standards then. Is this documented
anywhere? Is this is something that is going to change? I don't want
to write and app and have things "break" during and upgrade :)
Thanks for the response.
On Mon, 5 Feb 2001, Karel Zak wrote:
>
> On Mon, 29 Jan 2001, Keith Perry wrote:
>
> > Greetings,
> >
> > I notice some talk about date problems and interestingly enough planning
> > out an application in which I will need to be able to manipulate dates.
> > I notice however that there seems to be a discrepancy with the day or
> > week in 7.0.3
> >
> > ---
> >
> > pmhcc=# select date_part('dow','now'::timestamp);
> > date_part
> > -----------
> > 1
> > (1 row)
> >
> > pmhcc=# select to_char('now'::timestamp,'D');
> > to_char
> > ---------
> > 2
> > (1 row)
> >
>
> See:
>
> test=# select date_part('dow','2001-02-11'::timestamp);
> date_part
> -----------
> 0
>
> test=# select to_char('2001-02-11'::timestamp, 'D');
> to_char
> ---------
> 1
>
>
> date_part is based on zero - use range 0-6
> to_char is based on one - use range 1-7
>
> Karel
>
Re: Problem with Day of Week
От:
<keith@vcsn.com>
Дата:
Always- I think I'll use the to_char since I think you all are saying that that is ISO or at least POSIX. On Mon, 5 Feb 2001, Karel Zak wrote: > > On Mon, 5 Feb 2001 keith@vcsn.com wrote: > > > Ok, so there is actually two standards then. Is this documented > > anywhere? Is this is something that is going to change? I don't want > > to write and app and have things "break" during and upgrade :) > > I mean you can be caseful. Not changes planned here. > > date_part() is not documented to much in detail, but formatting > functions are described good. > > Karel >
