[postgis-users] new projection for Postgis

[Mateusz Loskot]

Frank Koormann wrote:
> What does
>
>         SELECT srid FROM spatial_ref_sys WHERE srtext ~ 'DHDN';
>
> return? For me (running PostGIS 1.2.1) this results in 10 matching
> entries.

Change this query to read:

SELECT srid, srtext FROM spatial_ref_sys WHERE srtext ~ 'DHDN';

and you will see what it does.
For more details, walk through following section of PostgreSQL manual:

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

Shortly, the query fetches all rows with DHDN token in srtext column,
similarly to LIKE '%DHDN%' but ~ operator comes from regular expressions
world.

Cheers
-- 
Mateusz Loskot
http://mateusz.loskot.net