Logo de pgRouting

Iniciando rápidamente pgRouting

pgRouting es una extensión y añade enrutamiento y funcionalidad de análisis de redes a las bases de datos PostGIS/PostgreSQL .

Este inicio rápido describe cómo abrir una base de datos con la línea de comandos y ejecutar una consulta básica de ruta más corta con la muestra de datos de prueba.

Ejecutando pgRouting

Desde el menú Applications ‣ Accessories ‣ Terminal y conectar a la base de datos``pgrouting``:

psql -U user pgrouting
  • Escribir \d y esto enlistará todas las tablas disponibles:
                List of relations
 Schema |        Name         |   Type   | Owner
--------+---------------------+----------+-------
 public | classes             | table    | user
 public | geography_columns   | view     | user
 public | geometry_columns    | view     | user
 public | nodes               | table    | user
 public | raster_columns      | view     | user
 public | raster_overviews    | view     | user
 public | relation_ways       | table    | user
 public | relations           | table    | user
 public | spatial_ref_sys     | table    | user
 public | types               | table    | user
 public | vertices_tmp        | table    | user
 public | vertices_tmp_id_seq | sequence | user
 public | way_tag             | table    | user
 public | ways                | table    | user
(14 rows)
  • Ejecutar la función de ruta más corta de Dijkstra:
SELECT seq, id1 AS node, id2 AS edge, cost
        FROM pgr_dijkstra('
                SELECT gid::int as id, source::int, target::int,
                        length::float8 as cost FROM ways',
                100, 600, false, false
        );

 seq | node | edge  |        cost
-----+------+-------+---------------------
   0 |  100 |   115 |  0.0605959823538948
   1 |   99 |  2972 |   0.197600739218643
   2 | 2151 |  3783 |  0.0139212050887606
 ... |  ... |   ... |                 ...
  52 |  599 |   732 |  0.0390125147117973
  53 |  600 |    -1 |                   0
(54 rows)
  • Para obtener la geometría, ligar los resultados con la geometría de los caminos:
SELECT seq, id2 AS edge, rpad(b.the_geom,60,' ') AS "the_geom (truncated)"
        FROM pgr_dijkstra('
                SELECT gid::int as id, source::int, target::int,
                        length::float8 as cost FROM ways',
                100, 600, false, false
        ) a INNER JOIN ways b ON (a.id2 = b.gid) ORDER BY seq;

 seq | edge  |                     the_geom (truncated)
-----+-------+--------------------------------------------------------------
   0 |   115 | 0102000020E610000002000000012D0208C4B0F2BFBD2DA237267A4A40E5
   1 |  2972 | 0102000020E610000002000000622B0DA1EFB3F2BF65236B685E7A4A4001
   2 |  3783 | 0102000020E610000002000000BD4571D8C7B4F2BFB2648EE55D7A4A4062
 ... |   ... |                                                          ...
  52 |   732 | 0102000020E6100000020000006B48DC63E903F3BF84CCDFCECF7B4A40E9
(53 rows)
  • Con \q nos salimos de PostgreSQL.

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