Re: WITH clause

David Fetter kirjutas R, 12.12.2003 kell 20:13:
> Kind people,
>
> I'm looking to the SQL WITH clause as a way to get better regex
> support in PostgreSQL. I've been chatting a little bit about this,
> and here's an idea for a behavior. Implementation details TBD.
>
> WITH res = match (x.foo, '([0-9]+)x([0-9]+)')
> SELECT *
> FROM x
> WHERE y = res[2]
> OR y = res[3];

why not use current standard syntax

SELECT x.*
FROM x,
(select match (x.foo, '([0-9]+)x([0-9]+)')
from x innerx
where innerx.pk = x.pk
) as res
HAVING y = get_match_group(res, 2)
OR y = get_match_group(res, 3)
;

with functions match(str,regex) which returns a match object
and get_match_group which extracts matched groups from it.

---------------
Hannu