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Thread: Arithmetic operation on DATE

Arithmetic operation on DATE

From
"macky"
Date:
is it possible to add a date datatype column to a number resulting to a
date......


theoretically it should do this,,,

X is in months

date + X = date

-->  2001-08-20 + 6 = 2002-02-20

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Re: Arithmetic operation on DATE

From
"Jason Wong"
Date:
I know you can do it for days, thus:

   expires = CURRENT_TIMESTAMP + 10

would be 10 days from now. Don't know about months though.

HTH
--
Jason Wong
Gremlins Associates
www.gremlins.com.hk


----- Original Message -----
From: macky <macky@edsamail.com>
To: <pgsql-novice@postgresql.org>; <pgsql-sql@postgresql.org>
Sent: Monday, August 13, 2001 5:48 PM
Subject: [NOVICE] Arithmetic operation on DATE


> is it possible to add a date datatype column to a number resulting to a
> date......
>
>
> theoretically it should do this,,,
>
> X is in months
>
> date + X = date
>
> -->  2001-08-20 + 6 = 2002-02-20
>

Re: [SQL] Arithmetic operation on DATE

From
Christopher Sawtell
Date:
On Mon, 13 Aug 2001 21:48, macky wrote:
> is it possible to add a date datatype column to a number resulting to a
> date......

chris=# select date(CURRENT_TIMESTAMP);
    date
------------
 2001-08-13
(1 row)

chris=# select date(CURRENT_TIMESTAMP) + '6 @days'::interval;
        ?column?
------------------------
 2001-08-19 00:00:00+12
(1 row)

chris=# select date(date(CURRENT_TIMESTAMP) + '6 @days'::interval);
    date
------------
 2001-08-19
(1 row)

That what you want?

> theoretically it should do this,,,
>
> X is in months
>
> date + X = date
>
> -->  2001-08-20 + 6 = 2002-02-20
>
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> The information contained in this message (including any attachments)
> is confidential and intended solely for the attention and use of the
> named addressee(s). It must not be copied, distributed nor disclosed
> to any person. If you are not the intended recipient, please delete
> it from your system and notify sender immediately. Any disclosure,
> copying or distribution thereof or any action taken or omitted to be
> taken in reliance thereon is prohibited and may be unlawful.
> ----------------------------------------------------------------------
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster

Re: [SQL] Arithmetic operation on DATE

From
Karel Zak
Date:
On Mon, Aug 13, 2001 at 05:48:57PM +0800, macky wrote:
> is it possible to add a date datatype column to a number resulting to a
> date......
>
>
> theoretically it should do this,,,
>
> X is in months
>
> date + X = date
>
> -->  2001-08-20 + 6 = 2002-02-20

test=# select '2001-08-20'::date + '6months'::interval;
        ?column?
------------------------
 2002-02-20 00:00:00+01
(1 row)


 ..see docs about the "interval" datetype.

            Karel

--
 Karel Zak  <zakkr@zf.jcu.cz>
 http://home.zf.jcu.cz/~zakkr/

 C, PostgreSQL, PHP, WWW, http://docs.linux.cz, http://mape.jcu.cz

Re: [SQL] Re: Arithmetic operation on DATE

From
"Josh Berkus"
Date:
Jason, Macky,

>    expires = CURRENT_TIMESTAMP + 10
>
> would be 10 days from now. Don't know about months though.

That's almost correct.  Try:

expires := current_timestamp + '10 days'::INTERVAL

For macky's question:

expires := current_timestamp + '6 months'::INTERVAL

I'll be posting a FAQ on data/time datatypes in PostgreSQL soon.

-Josh Berkus


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