-- crea geotabella vuota "vertici_rete"
SELECT DropGeoTable( "vertici_rete");
CREATE TABLE "vertici_rete" (
"pk_uid" INTEGER PRIMARY KEY AUTOINCREMENT, 
"name" INTEGER);
SELECT AddGeometryColumn ('vertici_rete','geom',4326,'POINT','XY');

-- popola la geotabella "vertici_rete" 
-- con il primo e ultimo vertice della rete
INSERT INTO "vertici_rete" 
SELECT NULL, "name", ST_PointN(geom,1) as geom
FROM "roads" 
UNION ALL
SELECT NULL, "name", ST_PointN(geom,-1) as geom 
FROM "roads";
SELECT RecoverGeometryColumn('vertici_rete','geom',4326,'POINT','XY')

-- crea geotabella vertici_rete2
SELECT DropGeoTable( "vertici_rete1");
CREATE TABLE "vertici_rete1" AS
SELECT "name", ST_Boundary(geom) as geom
FROM "roads" ;
SELECT RecoverGeometryColumn('vertici_rete1','geom',4326,'MULTIPOINT','XY');

-- crea geotabella vertici2
SELECT DropGeoTable( "vertici_rete2");
SELECT ElementaryGeometries( 'vertici_rete1' ,
                             'geom' , 
				     'vertici_rete2' ,
				     'out_pk' , 
				     'out_multi_id', 1 ) as num,
				     'point splitted' as label;

-- cancella la geotabella non più utile
SELECT DropGeoTable( "vertici_rete1");