From: greg@turnstep.com
To: pgsql-sql@postgresql.org
Cc: sgnerd@yahoo.com.sg
Subject: Re: Equivalent of Reverse() functions
Date: Sat, 29 Nov 2003 17:51:10 -0000
Message-ID: <c868f12fac1afa8fcf1a4e25eb33e81d@biglumber.com> (raw)
In-Reply-To: <00cb01c3b4b2$c23d9520$7502a8c0@hdsc.com>
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> I am migrating an SQL Server 2000 database to Postgres 7.3.4 running
> on RH Linux 7.2. While migrating I encounter SQL Server REVERSE( )
> function, seems no such functions at Postgres.
>
> Is there a equivalent function available at Postgres? Please
> shed some light
No. If you have plperl installed, as somebody already posted, you can
take advantage of perl's built in reverse() function. Here is a
plpgsql version:
CREATE OR REPLACE FUNCTION reverse(TEXT) RETURNS TEXT AS '
DECLARE
original ALIAS FOR $1;
reversed TEXT := \'\';
onechar VARCHAR;
mypos INTEGER;
BEGIN
SELECT LENGTH(original) INTO mypos;
LOOP
EXIT WHEN mypos < 1;
SELECT substring(original FROM mypos FOR 1) INTO onechar;
reversed := reversed || onechar;
mypos := mypos -1;
END LOOP;
RETURN reversed;
END
' LANGUAGE plpgsql IMMUTABLE RETURNS NULL ON NULL INPUT;
pg=> SELECT reverse('A man, a plan, a canal, Panama');
reverse
- --------------------------------
amanap ,lanac a ,nalp a ,nam A
- --
Greg Sabino Mullane greg@turnstep.com
PGP Key: 0x14964AC8 200311291246
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To: pgsql-sql@postgresql.org
Cc: greg@turnstep.com, sgnerd@yahoo.com.sg
Subject: Re: Equivalent of Reverse() functions
In-Reply-To: <c868f12fac1afa8fcf1a4e25eb33e81d@biglumber.com>
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