[postgis-users] functions

[Jonatan Malaver]

Another question, what can I do to improve performance on the query? The query can take 2 seconds or more.

From: postgis-users-bounces at lists.osgeo.org [mailto:postgis-users-bounces at lists.osgeo.org] On Behalf Of Jonatan Malaver
Sent: Monday, December 09, 2013 8:52 PM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] functions

Thank you!!!

Jon

From: postgis-users-bounces at lists.osgeo.org [mailto:postgis-users-bounces at lists.osgeo.org] On Behalf Of tommaso
Sent: Monday, December 09, 2013 12:57 PM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] functions

This should work:

create or replace function flow(integer) RETURNS TABLE (gid int, geom geometry, geojson text) AS
$$

WITH RECURSIVE flow(gid, geom) AS (

    SELECT e.gid, e.geom FROM electric_line e, fuses f WHERE ST_DWithin(ST_AsText(e.geom)::geometry, ST_AsText(f.geom)::geometry, 0.01) AND f.gid=$1

  UNION ALL

    SELECT n.gid, n.geom

    FROM electric_line n, flow f

    WHERE ST_DWithin(ST_EndPoint(f.geom),ST_StartPoint(n.geom),0.01)

  )

SELECT *, ST_ASGeoJSON(ST_Transform(geom,4326),6) AS geojson

FROM flow;

 $$
LANGUAGE SQL;


SELECT * FROM flow(1);


On 12/09/2013 03:57 PM, Jonatan Malaver wrote:
Hello,

  I'm new to postgis/postgresql. I was wondering if anyone could tell me how to make a function out of this sql query:

WITH RECURSIVE flow(gid, geom) AS (
    SELECT e.gid, e.geom FROM electric_line e, fuses f WHERE ST_DWithin(ST_AsText(e.geom)::geometry, ST_AsText(f.geom)::geometry, 0.01) AND f.gid=' . $_GET['fuse'] . '
  UNION ALL
    SELECT n.gid, n.geom
    FROM electric_line n, flow f
    WHERE ST_DWithin(ST_EndPoint(f.geom),ST_StartPoint(n.geom),0.01)
  )
SELECT *, ST_ASGeoJSON(ST_Transform(geom,4326),6) AS geojson
FROM flow;

   I'd like to make a function flow(gid)

Thanks,

Jon




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