Hello, Did you try ST_Intersects ? I think it's the more appopriate fonction to achieve that.
Hugues [email protected] a écrit : Hi everybody, I'm new in PostGIS world and I'm in trouble with points and linestring. As title said I have a problem verifying that a point belongs to a linestring. I've created those table with those commands: CREATE TABLE Punti ( Nome VARCHAR(20) PRIMARY KEY, Point GEOMETRY(POINT, 26910) NOT NULL ); CREATE TABLE Strade ( Nome VARCHAR(20) PRIMARY KEY, Road GEOMETRY(LINESTRING, 26910) NOT NULL ); Those are two of my inserts: INSERT INTO Strade VALUES('Strada1', ST_GeomFromText('LINESTRING(50 20, 30 20)', 26910)); INSERT INTO Punti VALUES ('Punto1', ST_GeomFromText('POINT(43 23)', 26910)); I added a point in linestring Strada1: UPDATE Strade SET road=ST_AddPoint(road,ST_GeomFromText('POINT(43 23)'), 1) WHERE nome='Strada1'; And this is the problematic query: SELECT Strade.nome, ST_Within(Punti.point, Strade.road) FROM Strade, Punti WHERE Strade.nome='Strada1' AND Punti.nome='Punto1'; I supposed ST_Within returns true but it returns false. As ST_Within also ST_Contains, ST_ContainsProperly, and others returns false. Can you tell where is my error and how to solve it? Thaks a lot Andrea -- View this message in context: http://postgis.17.x6.nabble.com/Select-a-point-that-belongs-to-a-linestring-tp5003990.html Sent from the PostGIS - User mailing list archive at Nabble.com. _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
