pggeodb.nancy.inra.fr/db_cefs - db_cefs on pggeodb.nancy.inra.fr

Function: equals

Schema

topology

Owner

postgres

Descriptions

args: tg1, tg2 - Returns true if two topogeometries are composed of the same topology primitives.

Options

Definition

CREATE OR REPLACE FUNCTION topology.equals (
 tg1 topology.topogeometry,
 tg2 topology.topogeometry
)
RETURNS boolean AS
$span$
DECLARE
 rec RECORD;
 toponame varchar;
 query text;
BEGIN

 IF tg1.topology_id != tg2.topology_id THEN
   -- TODO: revert to ::geometry instead ?
   RAISE EXCEPTION 'Cannot compare TopoGeometries from different topologies';
 END IF;

 -- Not the same type, not equal
 IF tg1.type != tg2.type THEN
   RETURN FALSE;
 END IF;

 -- Geometry collection are not currently supported
 IF tg2.type = 4 THEN
   RAISE EXCEPTION 'GeometryCollection are not supported by equals()';
 END IF;

       -- Get topology name
       SELECT name FROM topology.topology into toponame
               WHERE id = tg1.topology_id;

 -- Two geometries are equal if they are composed by
 -- the same TopoElements
 FOR rec IN EXECUTE 'SELECT * FROM '
   || ' topology.GetTopoGeomElements('
   || quote_literal(toponame) || ', '
   || tg1.layer_id || ',' || tg1.id || ') '
   || ' EXCEPT SELECT * FROM '
   || ' topology.GetTopogeomElements('
   || quote_literal(toponame) || ', '
   || tg2.layer_id || ',' || tg2.id || ');'
 LOOP
   RETURN FALSE;
 END LOOP;

 FOR rec IN EXECUTE 'SELECT * FROM '
   || ' topology.GetTopoGeomElements('
   || quote_literal(toponame) || ', '
   || tg2.layer_id || ',' || tg2.id || ')'
   || ' EXCEPT SELECT * FROM '
   || ' topology.GetTopogeomElements('
   || quote_literal(toponame) || ', '
   || tg1.layer_id || ',' || tg1.id || '); '
 LOOP
   RETURN FALSE;
 END LOOP;
 RETURN TRUE;
END
$span$
LANGUAGE 'plpgsql'
STABLE
RETURNS NULL ON NULL INPUT
SECURITY INVOKER
COST 100;

COMMENT ON FUNCTION topology.equals(tg1 topology.topogeometry, tg2 topology.topogeometry)
IS 'args: tg1, tg2 - Returns true if two topogeometries are composed of the same topology primitives.';

This file was generated with SQL Manager for PostgreSQL (www.pgsqlmanager.com) at 13/03/2014 13:23