Thread: regexp_replace

Hi all,

I would like to change a sub-string in a text-field by using

UPDATE tablename SET
fieldname=regexp_replace(fieldname,old_sub_string,new_sub_string)
WHERE (fieldname like '%old_sub_string%')

In priniciple, it works. However, only one occurence of old_sub_string
is replaced and further not. Which syntax has to be used to replace
all old_sub_strings by new_sub_string in a text-field at once? I have
seen something like '\&' in the docs and tried it, but I failed.

Any Idea? Thanks a lot!

Ciao,
Tino

am  Mon, dem 23.07.2007, um  7:50:35 -0700 mailte polen.t2006@freenet.de folgendes:
> Hi all,
>
> I would like to change a sub-string in a text-field by using
>
> UPDATE tablename SET
> fieldname=regexp_replace(fieldname,old_sub_string,new_sub_string)
> WHERE (fieldname like '%old_sub_string%')
>
> In priniciple, it works. However, only one occurence of old_sub_string
> is replaced and further not. Which syntax has to be used to replace
> all old_sub_strings by new_sub_string in a text-field at once? I have
> seen something like '\&' in the docs and tried it, but I failed.
>
> Any Idea? Thanks a lot!

No problem, add a 'g' as extra parameter to your regexp_replace() -
function. See:

test=> select regexp_replace('xxaxxxxaxxxa','a','A');
 regexp_replace
----------------
 xxAxxxxaxxxa
(1 row)

test=*> select regexp_replace('xxaxxxxaxxxa','a','A','g');
 regexp_replace
----------------
 xxAxxxxAxxxA
(1 row)



Andreas
--
Andreas Kretschmer
Kontakt:  Heynitz: 035242/47150,   D1: 0160/7141639 (mehr: -> Header)
GnuPG-ID:   0x3FFF606C, privat 0x7F4584DA   http://wwwkeys.de.pgp.net

On Mon, Jul 23, 2007 at 07:50:35AM -0700, polen.t2006@freenet.de wrote:
> I would like to change a sub-string in a text-field by using
>
> UPDATE tablename SET
> fieldname=regexp_replace(fieldname,old_sub_string,new_sub_string)
> WHERE (fieldname like '%old_sub_string%')
>
> In priniciple, it works. However, only one occurence of old_sub_string
> is replaced and further not. Which syntax has to be used to replace
> all old_sub_strings by new_sub_string in a text-field at once?

regexp_replace(fieldname, old_sub_string, new_sub_string, 'g')

For more information search for regexp_replace in the Pattern
Matching section of the Functions and Operators chapter of the
documentation.

http://www.postgresql.org/docs/8.2/interactive/functions-matching.html

--
Michael Fuhr