[postgis-users] Problem using set-returning functions

[Markus Schaber]

Hi, Regina,

Obe, Regina DND\MIS wrote:

> Actually I suspect no set returning function created in pgsql will work
> the way you are trying to do it.  Not sure why.  The dump is done in c
> and plugged in and I think it explicitly generates a tuple in the target
> set for every output.
> 
> Try rewriting your function to something like this and see if it works
> 
> CREATE OR REPLACE FUNCTION generate_x (geom geometry)
> RETURNS SETOF double precision AS
> '
>     SELECT X(geometryn($1,index))
> 	FROM generate_series(1, npoints($1)) index;
> 
> ' LANGUAGE 'sql' IMMUTABLE STRICT;

Yes, it seems to work. This will solve the OPs case.


But it is still a good question whether it is possible to accomplish
this using plpgsql.

Thanks,
Markus

-- 
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf.     | Software Development GIS

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