Обсуждение: Regexp_replace question / help needed

Christopher Molnar <cmolnar@ourworldservices.com> writes:
> I have a string (like 40,000 with different length and number of
> components) of them in a field named "externalurl". I need to replace the
> final "/" of the string with "&file=" while preserving the filename and
> extension following the "/".
> The closest I can get is:
> regexp_replace('http://test.com/test/testfile.php','/[^/]*$','&file=')

There's more than one way to do it.  You could use capturing parens:

regexp_replace('http://test.com/test/testfile.php','/([^/]*)$','&file=\1')

or you could use a lookahead constraint:

regexp_replace('http://test.com/test/testfile.php','/(?=[^/]*$)','&file=')

            regards, tom lane

Hi,
I guess capture will help you look at
http://www.postgresql.org/docs/9.0/static/functions-matching.html

SELECT regexp_replace('http://test.com/test/testfile.php',
'^(.*)/(.*\.php)$', E'\\1&file=\\2', 'g')

2015-12-09 22:58 GMT+01:00 Christopher Molnar <cmolnar@ourworldservices.com>:
> Hello,
>
> I am running into a problem and need some pointers on regexp_replace - I
> can't seem to find an answer in any of the online resources.
>
> I have a string (like 40,000 with different length and number of components)
> of them in a field named "externalurl". I need to replace the final "/" of
> the string with "&file=" while preserving the filename and extension
> following the "/".
>
> The closest I can get is:
>
> regexp_replace('http://test.com/test/testfile.php','/[^/]*$','&file=')
>
> however this looses the file name and returns:
>
> http://test.com/test&file=
>
> What I am looking for is:
>
> http://test.com/test&file=testfile.php
>
> as a result.
>
> Would anyone here point me in the right direction?
>
> Thanks!
> -Chris

Christopher Molnar <cmolnar@ourworldservices.com> writes:

> Hello,
>
> I am running into a problem and need some pointers on regexp_replace - I can't seem to find an answer in any of the
onlineresources. 
>
> I have a string (like 40,000 with different length and number of components) of them in a field named "externalurl".
Ineed to replace the final "/" of the string with 
> "&file=" while preserving the filename and extension following the "/".
>
> The closest I can get is:
>
> regexp_replace('http://test.com/test/testfile.php','/[^/]*$','&file=') 
>
> however this looses the file name and returns:
>
> http://test.com/test&file=
>
> What I am looking for is:
>
> http://test.com/test&file=testfile.php
>
> as a result.
>
> Would anyone here point me in the right direction?


> select regexp_replace('http://foo/wow/blah/zzz.php', '/([^/]*)$', '&file=\1');
          regexp_replace
----------------------------------
 http://foo/wow/blah&file=zzz.php
(1 row)


>
> Thanks!
> -Chris
>

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Jerry Sievers
Postgres DBA/Development Consulting
e: postgres.consulting@comcast.net
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