Hi, i have to create an agregation function.. what is the syntax.
The function to be agregation is :
DROP FUNCTION "polygon_agregation"(polygon);
CREATE FUNCTION "polygon_agregation"(polygon) RETURNS box AS 'DECLARE
polygons_to_agregate ALIAS FOR $1
BEGIN
agregated_polygons = NULL;
FOR poly IN polygons_to_agregate LOOP
IF agregated_polygons = NULL THEN agregated_polygons = box(poly);
agregated_polygons = box(agregated_polygons, box(poly));
END LOOP;
RETURN agregated_polygons,
END' LANGUAGE 'plpgsql'
Thanx
Pierre-Yves Landuré
