Re: psql can't subtract - Mailing list pgsql-general

On 25/03/11 15:29, Rob Sargent wrote:
> Running 9.0.3 (client and server)

> select distinct
> substring(
...
> position( 'xmlns=' in substring(xml_text,1,300)) + length('xmlns="'),
> 100))) -1
...
> gives
> ERROR: negative substring length not allowed.

If there is no match the initial position will be zero. Minus one will
give you a negative substring length.

--
   Richard Huxton
   Archonet Ltd