From: Gnanakumar <gnanam@zoniac.com>
To: 'Dmitriy Igrishin' <dmitigr@gmail.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Is it possible to get DISTINCT rows from RETURNING clause?
Date: Mon, 21 Feb 2011 17:20:41 +0530
Message-ID: <007701cbd1bd$927a3de0$b76eb9a0$@com> (raw)
In-Reply-To: <AANLkTi=UDPRE7rDGeapdKm2ZU-t=N7=JsKn3VA_f2NBG@mail.gmail.com>
References: <003d01cbce71$1eaf1c90$5c0d55b0$@com>
<001e01cbcf30$e35cca00$aa165e00$@com>
<AANLkTi=UDPRE7rDGeapdKm2ZU-t=N7=JsKn3VA_f2NBG@mail.gmail.com>
Hi Dmitriy Igrishin,
Thanks. That's a good idea too.
From: Dmitriy Igrishin [mailto:dmitigr@gmail.com]
Sent: Saturday, February 19, 2011 3:31 PM
To: gnanam@zoniac.com
Cc: pgsql-sql@postgresql.org
Subject: Re: [SQL] Is it possible to get DISTINCT rows from RETURNING clause?
Hey Gnanakumar,
You can wrap you UPDATE query into SQL function returning TABLE, e.g:
CREATE OR REPLACE FUNCTION public.update_mytable()
RETURNS TABLE(email text, column1 text, column2 text, column3 text)
LANGUAGE sql
AS $function$
UPDATE MYTABLE SET ABOOLEANCOLUMN = true FROM MYTEMPTABLE WHERE EMAIL =
MYTEMPTABLE.EMAIL RETURNING EMAIL, COLUMN1, COLUMN2, COLUMN3;
$function$;
Next you can write, e.g:
SELECT DISTINCT * FROM
(SELECT update_mytable()) AS foo(email, column1, column2, column3);
And so on.
2011/2/18 Gnanakumar <gnanam@zoniac.com>
Any ideas?
-----Original Message-----
From: Gnanakumar [mailto:gnanam@zoniac.com]
Sent: Thursday, February 17, 2011 12:36 PM
To: pgsql-sql@postgresql.org
Subject: Is it possible to get DISTINCT rows from RETURNING clause?
Hi,
Is it possible to get DISTINCT rows from an UPDATE statement using RETURNING
clause?
"MYTABLE" columns are:
APRIMARYKEYCOLUMN
ABOOLEANCOLUMN
EMAIL
COLUMN1
COLUMN2
COLUMN3
UPDATE using RETURNING clause query:
UPDATE MYTABLE SET ABOOLEANCOLUMN = true FROM MYTEMPTABLE WHERE EMAIL =
MYTEMPTABLE.EMAIL RETURNING EMAIL, COLUMN1, COLUMN2, COLUMN3;
Here in this case, I expect to return distinct rows from these columns:
EMAIL, COLUMN1, COLUMN2, COLUMN3.
I even tried out some ways of getting distinct rows, but it doesn't work.
Though I can still solve this at application layer, I'm trying to find
whether this could be controlled at query-level. Any different
ideas/suggestions are appreciated.
Regards,
Gnanam
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// Dmitriy.
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Cc: gnanam@zoniac.com, dmitigr@gmail.com
Subject: Re: Is it possible to get DISTINCT rows from RETURNING clause?
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