Collection of useful SQL commands

JOIN two tables

SELECT
        count(gid) AS links,
        sum(a.cost) AS cost,
        sum(length) AS length

FROM shortest_path(
        'SELECT gid AS id,
                source::integer,
                target::integer,
                length::double precision AS cost
        FROM <TABLE A>
        WHERE <...>,
        false,
        false
) AS a LEFT JOIN <TABLE B> ON (a.gid = gid)

Note

If you have some SQL commands to share, that are useful for pgRouting, send an email to project@pgrouting.org for further informations.