Dear all,
I have x,y coordinates in CSV file which i copy to postgres database using:
COPY links (id,from_node,to_node,....) FROM 'path/to/file' DELIMITER ',' CSV
HEADER;COPY nodes (id,point_x,point_y...) FROM 'path/to/file' DELIMITER ',' CSV
HEADER;
I have then written a trigger that would generate the_geom from number 2
(pointx,point_y);
I then use the id of Number 2 to generate line geometries for Number 1, where
from_node and to_node are the beginning and end points of the line.
I use the following triggers:
BEGINIF NEW.the_geom is nullTHENINSERT INTO NODES (the_geom) (SELECT
SetSRID(MakePoint(new.point_x, new.point_y), -1)FROM nodes) ;ELSE (for
circumstances where i have the_geom and not the point_x and point_y)NEW.point_x
= X(NEW.the_geom); NEW.point_y = Y(NEW.the_geom); END IF;RETURN NEW;ENDCREATE
TRIGGER calc_point_insert AFTER INSERT ON nodes FOR EACH ROW EXECUTE
PROCEDURE calc_point();CREATE TRIGGER calc_point_update
AFTERUPDATE
ON nodes
FOR EACH ROW
EXECUTE PROCEDURE calc_point();
This runs with no end and if i remove the bold NEW i get an error the_geom
doesn't exist.
On the Number 1 Side I have this that is for joining points, which i thought
should work but doesnt work.
CREATE OR REPLACE FUNCTION update_links() RETURNS "trigger"
AS$BODY$BEGINUPDATE links SET the_geom = MakeLine(NEW.the_geom,ends.the_geom)
FROM nodes As ends WHERE NEW.id = links.from_node and ends.id =
links.to_node; UPDATE links SET the_geom =
MakeLine(starts.the_geom,NEW.the_geom) FROM nodes As starts
WHERE starts.id = links.from_node and NEW.id =links.to_node; RETURN
NEW;END$BODY$CREATE TRIGGER update_links_insert AFTER INSERT ON nodes FOR
EACH ROW EXECUTE PROCEDURE update_links();
Similarly for update.
Please help me with these triggers
Thank you
Broun Uganda
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