pgRouting Quickstart

pgRouting is an extension of PostGIS and adds routing functionality to PostGIS/PostgreSQL.

This Quick Start describes how to open a database with the command line and run a basic shortest path query with the sample test data.

Running pgRouting

• Open a Applications ‣ Accessories ‣ Terminal window and connect to the pgrouting database:

psql -U user pgrouting

• Type \d will list you all available tables:

                      List of relations
 Schema |        Name         |   Type   |  Owner
--------+---------------------+----------+----------
 public | geography_columns   | view     | postgres
 public | geometry_columns    | table    | postgres
 public | spatial_ref_sys     | table    | postgres
 public | vertices_tmp        | table    | postgres
 public | vertices_tmp_id_seq | sequence | postgres
 public | ways                | table    | postgres
(6 rows)

• Run the Dijkstra shortest path function:

SELECT * FROM shortest_path('
                SELECT gid as id,
                         source::integer,
                         target::integer,
                         length::double precision as cost
                        FROM ways',
                605, 359, false, false);

 vertex_id | edge_id |        cost
-----------+---------+---------------------
       605 |    5575 |  0.0717467247513547
      1679 |    2095 |   0.148344716070272
       588 |    2094 |  0.0611856933258344
       ... |     ... |  ...
       359 |      -1 |                   0
(82 rows)

• Try the wrapper function to get the routing result in a different format:

SELECT gid, AsText(the_geom) AS the_geom
        FROM dijkstra_sp('ways', 605, 359);

  gid   |                              the_geom
--------+---------------------------------------------------------------
    168 | MULTILINESTRING((2.1633077 41.3802886,2.1637094 41.3803008))
    169 | MULTILINESTRING((2.1637094 41.3803008,2.1638796 41.3803093))
    170 | MULTILINESTRING((2.1638796 41.3803093,2.1640527 41.3803265))
    ... | ...
   5575 | MULTILINESTRING((2.1436976 41.3897581,2.143876 41.3903893))
(81 rows)

• With \q command leave the PostgreSQL shell.

What next?

• pgRouting Website - Visit the project website http://www.pgrouting.org to learn more about pgRouting.
• Workshop on DVD - Included on this LiveDVD is the FOSS4G 2010 pgRouting workshop “FOSS4G routing with pgRouting tools, OpenStreetMap road data and GeoEx”, available in: /usr/share/pgrouting/workshop/

Note

To update to the latest version of the tutorial, open a terminal window, then run sudo apt-get update && apt-get upgrade pgrouting-workshop