title: Pgrouting insert od columns into pgr_dijkstra query
body: <p>I try to calculate travels between a pair list of 2 layers : origin and destination.
  I create a table of combinaison between this two layers with vertices id in vertices_o for origin and vertices_d for destination.
  I call the columns into this query.</p>
  <p><strong>The combination table</strong></p>
  <p><a href="https://i.stack.imgur.com/F0uxt.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/F0uxt.png" alt="![enter image description here" /></a></p>
  <p><strong>The query</strong></p>
  <pre><code>CREATE TABLE travel.results AS
  (SELECT seq, path_seq, node,  edge, di.cost, agg_cost, the_geom FROM pgr_dijkstra('
              SELECT gid as id,
               source::integer,
               target::integer,
               length_m::double precision as cost
              FROM travel.ways', 
              vertices_o, vertices_d, true) as di
  JOIN travel.ways ways_vertices_pgr
  ON di.edge = ways_vertices_pgr.gid);
  </code></pre>
  <p>He didn't recognize the columns vertices_o and vertices_d.</p>