How to create routable network by pgrouting with assign_vertex_id?

Question

I'm trying to create the routable network as per http://underdark.wordpress.com/2011/02/07/a-beginners-guide-to-pgrouting/and use assign_vertex_id. Do I still need to create the node table? How would code for creating network look like?

Answer 1

On this link is a very good tutorial about it.

You don't need the node table, you can use the your original table instead. First you have to add two columns to it, called source and target, both integer. After that you run the assign_vertex_id like this:

assign_vertex_id('<table>', float tolerance, '<geometry column', '<gid>')

So here is the whole code, where "ways" is the tablename:

ALTER TABLE ways ADD COLUMN source integer;
ALTER TABLE ways ADD COLUMN target integer;
SELECT assign_vertex_id('ways', 0.00001, 'the_geom', 'gid');