pgr_Dijkstra: iterate/loop through a table with multiple OD pairs one-by-one

Question

I have a table with 2 columns: column A with the startvertex and column B with endvertex.

How can I do a OD pairs shortest path?

It is with a loop I suppose, but how can this loop be implemented into pgr_Dijkstra? It's impossible do to all the OD pairs manually, so an iteration is necessary.

I have already a working query for pgr_Dijkstra for a single point-to-point, but the problem is to do it for all the OD-pairs one-by-one.

Answer 1

pgr_Dijkstra caan also solve 1->n and n->m shortest path. When you look at the function documentation you will see, that you can pass an array of start or end ID's.

SELECT * FROM pgr_dijkstra( 'SELECT id, source, target, cost, reverse_cost FROM edge_table', ARRAY[2,11], ARRAY[3,5], FALSE );

http://docs.pgrouting.org/2.4/en/pgr_dijkstra.html#pgr-dijkstra-many-to-many