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Thread: max (timestamp,timestamp)

max (timestamp,timestamp)

From
T E Schmitz
Date:
I tried the following query but the query fails as
"function max (timestamp w. timezone,timestamp w. timezone) does not exist"

SELECT id,

MAX(last_updated,
(SELECT MAX (last_updated) FROM  product_category_member WHERE
product_category_member.id =  product_category.id))

FROM product_category


product_category.last_updated and product_category_member.last_updated
are timestamps with timezone.


Is there any other way I can produce this result

-- 


Regards,

Tarlika Elisabeth Schmitz

Re: max (timestamp,timestamp)

From
"A. Kretschmer"
Date:
am  Mon, dem 13.11.2006, um 13:46:00 +0000 mailte T E Schmitz folgendes:
> I tried the following query but the query fails as
> "function max (timestamp w. timezone,timestamp w. timezone) does not exist"
> 
> SELECT id,
> 
> MAX(last_updated,
> (SELECT MAX (last_updated) FROM  product_category_member WHERE
> product_category_member.id =  product_category.id))
> 
> FROM product_category
> 
> 
> product_category.last_updated and product_category_member.last_updated
> are timestamps with timezone.

Really, there are no such function. Perhaps this can help you:

SELECT id, MAX(product_category.last_updated),
MAX(product_category_member.last_updated) from product_category,
product_category_member WHERE product_category_member.id =
product_category.id;

**untested**



Your fault is that there are no max(timestamp,timestamp) - funktion and
i think, you should read more about JOINs.


Andreas
-- 
Andreas Kretschmer
Kontakt:  Heynitz: 035242/47215,   D1: 0160/7141639 (mehr: -> Header)
GnuPG-ID:   0x3FFF606C, privat 0x7F4584DA   http://wwwkeys.de.pgp.net

Re: max (timestamp,timestamp)

From
imad
Date:
max (timestamptz, timestamptz) does not exist already. You need to
create a simple function in PLpgSQL something like

if a > breturn a;
elsereturn b;

Even an sql function will do the job here using case statement.

--Imad
www.EntepriseDB.com



On 11/13/06, A. Kretschmer <andreas.kretschmer@schollglas.com> wrote:
> am  Mon, dem 13.11.2006, um 13:46:00 +0000 mailte T E Schmitz folgendes:
> > I tried the following query but the query fails as
> > "function max (timestamp w. timezone,timestamp w. timezone) does not exist"
> >
> > SELECT id,
> >
> > MAX(last_updated,
> > (SELECT MAX (last_updated) FROM  product_category_member WHERE
> > product_category_member.id =  product_category.id))
> >
> > FROM product_category
> >
> >
> > product_category.last_updated and product_category_member.last_updated
> > are timestamps with timezone.
>
> Really, there are no such function. Perhaps this can help you:
>
> SELECT id, MAX(product_category.last_updated),
> MAX(product_category_member.last_updated) from product_category,
> product_category_member WHERE product_category_member.id =
> product_category.id;
>
> **untested**
>
>
>
> Your fault is that there are no max(timestamp,timestamp) - funktion and
> i think, you should read more about JOINs.
>
>
> Andreas
> --
> Andreas Kretschmer
> Kontakt:  Heynitz: 035242/47215,   D1: 0160/7141639 (mehr: -> Header)
> GnuPG-ID:   0x3FFF606C, privat 0x7F4584DA   http://wwwkeys.de.pgp.net
>
> ---------------------------(end of broadcast)---------------------------
> TIP 6: explain analyze is your friend
>

Re: max (timestamp,timestamp)

From
Michael Fuhr
Date:
On Mon, Nov 13, 2006 at 07:29:09PM +0500, imad wrote:
> max (timestamptz, timestamptz) does not exist already. You need to
> create a simple function in PLpgSQL something like
> 
> if a > b
> return a;
> else
> return b;

Since PostgreSQL 8.1 you can use GREATEST:

test=> SELECT greatest(1, 2);greatest 
----------       2
(1 row)

test=> SELECT greatest(2, 1);greatest 
----------       2
(1 row)

test=> SELECT greatest(6, 3, 1, 10, 9, 5, 2, 7, 8, 4);greatest 
----------      10
(1 row)

-- 
Michael Fuhr

Re: max (timestamp,timestamp)

From
T E Schmitz
Date:
Michael Fuhr wrote:
> On Mon, Nov 13, 2006 at 07:29:09PM +0500, imad wrote:
> 
>>max (timestamptz, timestamptz) does not exist already. You need to
>>create a simple function in PLpgSQL something like
>>
>>if a > b
>>return a;
>>else
>>return b;
> 
> 
> Since PostgreSQL 8.1 you can use GREATEST:
> 
> test=> SELECT greatest(1, 2);

That'll be a handy feature! Unfortunately, my server is still on 7.4.


Thanks to everyone for the quick responses.
-- 


Regards,

Tarlika