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* Last day of month
@ 2004-02-25 12:35 Kumar <sgnerd@yahoo.com.sg>
0 siblings, 1 reply; 6+ messages in thread
From: Kumar @ 2004-02-25 12:35 UTC (permalink / raw)
To: pgsql-sql
Dear friends,
Postgres 7.3.4
How to find the last sunday/mon..../sat of any given month.
Thanks
Kumar
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: Last day of month
@ 2004-02-26 03:07 Greg Sabino Mullane <greg@turnstep.com>
parent: Kumar <sgnerd@yahoo.com.sg>
0 siblings, 4 replies; 6+ messages in thread
From: Greg Sabino Mullane @ 2004-02-26 03:07 UTC (permalink / raw)
To: pgsql-sql; +Cc: sgnerd@yahoo.com.sg
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
> How to find the last sunday/mon..../sat of any given month.
There is probably a smoother way to do it, but here is a
quick little function to do what you ask. Feed it a date
and a number, where 0 is Sunday, 1 is Monday, etc.
CREATE OR REPLACE FUNCTION lastday(date,int) RETURNS DATE AS '
DECLARE
match date;
tomorrow date;
BEGIN
SELECT TO_DATE(
(SELECT EXTRACT(\'year\' FROM $1) || \' \' ||
EXTRACT(\'month\' FROM $1) || \' 01\'),
\'YYYY MM DD\') INTO tomorrow;
LOOP
tomorrow := tomorrow + \'24 hours\'::interval;
IF (1 = EXTRACT(\'day\' FROM tomorrow) ) THEN
RETURN match;
END IF;
IF ($2 = EXTRACT(\'dow\' FROM tomorrow)) THEN
match := tomorrow;
END IF;
END LOOP;
END;
' LANGUAGE plpgsql;
- --
Greg Sabino Mullane greg@turnstep.com
PGP Key: 0x14964AC8 200402252206
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=AriI
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^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: Last day of month
@ 2004-02-26 04:27 Joe Conway <mail@joeconway.com>
parent: Greg Sabino Mullane <greg@turnstep.com>
3 siblings, 0 replies; 6+ messages in thread
From: Joe Conway @ 2004-02-26 04:27 UTC (permalink / raw)
To: Greg Sabino Mullane <greg@turnstep.com>; +Cc: pgsql-sql; sgnerd@yahoo.com.sg
Greg Sabino Mullane wrote:
>>How to find the last sunday/mon..../sat of any given month.
>
> There is probably a smoother way to do it, but here is a
> quick little function to do what you ask. Feed it a date
> and a number, where 0 is Sunday, 1 is Monday, etc.
How about this:
regression=# select date_trunc('month', current_date + '1 month'::interval);
date_trunc
---------------------
2004-03-01 00:00:00
(1 row)
Joe
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: Last day of month
@ 2004-02-26 04:30 Joe Conway <mail@joeconway.com>
parent: Greg Sabino Mullane <greg@turnstep.com>
3 siblings, 0 replies; 6+ messages in thread
From: Joe Conway @ 2004-02-26 04:30 UTC (permalink / raw)
To: Greg Sabino Mullane <greg@turnstep.com>; +Cc: pgsql-sql; sgnerd@yahoo.com.sg
Greg Sabino Mullane wrote:
>>How to find the last sunday/mon..../sat of any given month.
>
> There is probably a smoother way to do it, but here is a
> quick little function to do what you ask. Feed it a date
> and a number, where 0 is Sunday, 1 is Monday, etc.
oops...forget my last reply...I was a bit too quick on the draw. Try
this instead:
regression=# select date_trunc('month', current_date + '1
month'::interval) - '1 day'::interval;
?column?
---------------------
2004-02-29 00:00:00
(1 row)
Joe
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: Last day of month
@ 2004-02-26 14:45 Frank Bax <fbax@sympatico.ca>
parent: Greg Sabino Mullane <greg@turnstep.com>
3 siblings, 0 replies; 6+ messages in thread
From: Frank Bax @ 2004-02-26 14:45 UTC (permalink / raw)
To: pgsql-sql
At 11:30 PM 2/25/04, Joe Conway wrote:
>Greg Sabino Mullane wrote:
>>>How to find the last sunday/mon..../sat of any given month.
>>
>>There is probably a smoother way to do it, but here is a
>>quick little function to do what you ask. Feed it a date
>>and a number, where 0 is Sunday, 1 is Monday, etc.
>
>oops...forget my last reply...I was a bit too quick on the draw. Try this
>instead:
>
>regression=# select date_trunc('month', current_date + '1
>month'::interval) - '1 day'::interval;
> ?column?
>---------------------
> 2004-02-29 00:00:00
>(1 row)
>
>Joe
But the original request was for a specific day-of-week. So use Joe's
answer above to get last day of month, and use 'dow' to determine the
day-of-week of that day. Let's call that dow1. If the day-of-week being
asked for is dow2 then:
if dow1 < dow2
return (last-day-of-month - dow1 - 7 + dow2)
else
return (last-day-of-month - dow1 + dow2)
I'm no good at coding pgsql functions, so I'm not going to attempt proper
syntax.
Frank
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: Last day of month
@ 2004-02-26 16:37 Michael Chaney <mdchaney@michaelchaney.com>
parent: Greg Sabino Mullane <greg@turnstep.com>
3 siblings, 0 replies; 6+ messages in thread
From: Michael Chaney @ 2004-02-26 16:37 UTC (permalink / raw)
To: pgsql-sql; sgnerd@yahoo.com.sg
On Thu, Feb 26, 2004 at 03:07:52AM -0000, Greg Sabino Mullane wrote:
>
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
>
> > How to find the last sunday/mon..../sat of any given month.
>
> There is probably a smoother way to do it, but here is a
> quick little function to do what you ask. Feed it a date
> and a number, where 0 is Sunday, 1 is Monday, etc.
select date_trunc('month', current_date + '1 month'::interval) - '1 day'::interval +
(((3 - 7 - to_char(date_trunc('month', current_date + '1 month'::interval) -
'1 day'::interval,'D')::int) %7)||' days')::interval;
The "3" is the day of week (1 = Sunday, 7 = Saturday). This equation
will return the date of the last "x" of the current month. Change
"current_date" to be whatever date you wish to find the last "x" of.
Michael
--
Michael Darrin Chaney
mdchaney@michaelchaney.com
http://www.michaelchaney.com/
^ permalink raw reply [nested|flat] 6+ messages in thread
end of thread, other threads:[~2004-02-26 16:37 UTC | newest]
Thread overview: 6+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2004-02-25 12:35 Last day of month Kumar <sgnerd@yahoo.com.sg>
2004-02-26 03:07 ` Greg Sabino Mullane <greg@turnstep.com>
2004-02-26 04:27 ` Joe Conway <mail@joeconway.com>
2004-02-26 04:30 ` Joe Conway <mail@joeconway.com>
2004-02-26 14:45 ` Frank Bax <fbax@sympatico.ca>
2004-02-26 16:37 ` Michael Chaney <mdchaney@michaelchaney.com>
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