[Cartoweb-users] Table relations in Pgdijkstra

[Hassan]

I have a table say street_table which contains information about street such as gid, street_name, the_geom, source_id, target_id, and edge_id, traffic_direction, low_number, high_number
 
Using procedure as illustrated in the pgdijkstra documentation, I generate street_table_edges, and street_table_vertices. 
 
The street_table_edges has id, source, target, cost, reverse_cost.
 
The street_table_vertices has id, and geom_id.
 
1.  Based on the content of traffic_direction (a = both direction, b = one direction from high_number to low_number, c = one direction from low_number to high_number), I would like to alter the cost in street_table_edges to a large number to prevent a one way direction street from being used in shortest path calculation.
 
example 
 
For a segment A to B with traffic direction 'c' should have only normal cost associated from A => B but from a prohibitive cost from B => A.
 
2. What is the relation between source_id, target_id of street_table to source and target of street_table_edges. How can I use source_id, and target_id to access corresponding vertices in street_table_vertices. 
 
Thanks in advance!
 
- Hassan adekoya