Re: psql can't subtract

On Fri, Mar 25, 2011 at 09:29:57AM -0600, Rob Sargent wrote:
> Running 9.0.3 (client and server)
>
>
> Seems I cannot subtract 1 from the result of position.
>
> select distinct
> substring( substring(xml_text,1,300),
> position( 'xmlns=' in substring(xml_text,1,300)) +
> length('xmlns="'),
> position( '"' in (substring(substring(xml_text,1,300),
> position( 'xmlns=' in
> substring(xml_text,1,300)) + length('xmlns="'),
> 100)))
> ) as namespace
> from elements;

is there any particular reason why you're writing something that
complicated instead of using simple regexp?

select distinct regexp_replace( xml_text, '.*xmlns="([^"]+)".*', E'\\1') from elements;

Best regards,

depesz

--
The best thing about modern society is how easy it is to avoid contact with it.
http://depesz.com/