Problem with loop for pgr_Dijkstra

Question

I try to use pgr_Dijkstra through Postgis and Pgadmin to find the shortest path in a network between a lot of nodes.
So I thought I could to "automate" the process with a PLSQL query. Here is a query I simplified as example. It's a loop where I try to use pgr_Dijkstra between start nodes and end nodes having respectively _ids and _ide as id in the table network:

DO $$ DECLARE

_ids integer;
_ide integer;

BEGIN
    _ids:=161794;
    _ide:=161794;
    DROP TABLE IF EXISTS test_dijkstra;
    CREATE TABLE test_dijkstra(seq integer, node integer, edge integer, cost double precision);
    WHILE _ids <=161797 LOOP
        WHILE _ide <=161797 LOOP
            INSERT INTO test_dijkstra(seq, node, edge, cost)
            SELECT seq, id1 AS node, id2 AS edge, cost
            FROM pgr_Dijkstra('SELECT id, source, target, cost, x1, y1, x2, y2 FROM network', _ids, _ide, FALSE, FALSE);
            _ide:=_ide+3;
        END LOOP;
        _ids:=_ids+3;
    END LOOP;
END$$;  

My problem is that even with this simple example, the NOTICE tells me :

NOTICE:  Deprecated function
CONTEXT:  instruction SQL « INSERT INTO test_dijkstra(seq, node, edge, cost)
            SELECT seq, id1 AS node, id2 AS edge, cost
            FROM pgr_Dijkstra('SELECT id, source, target, cost, x1, y1, x2, y2 FROM network', _ids, _ide, FALSE, FALSE) »
fonction PL/pgsql inline_code_block, ligne 13 à instruction SQL 

I think the function doesn't want to have variables (_ids and _ide) as parameters, but I can't figure out why.

Is there a way to make it work? I have a lot of nodes, so I can't process pgr_Dijsktra manually for every couple!

Answer 1

Based on:

SELECT generate_series(161794, 161797, 3);    
 generate_series 
-----------------
          161794
          161797
(2 rows)

you can use the many to many signature of pgr_dijkstra: http://docs.pgrouting.org/2.2/en/src/dijkstra/doc/pgr_dijkstra.html#dijkstra-many-to-many

WITH
my_source_series AS (SELECT generate_series(161794, 161797, 3) AS sources,
my_target_series AS (SELECT generate_series(161794, 161797, 4) AS targets,
SELECT * FROM pgr_Dijkstra('SELECT id, source, target, cost FROM network',
 (select array_agg(sources) FROM my_source_series),
 (select array_agg(targets) FROM my_target_series),
 FALSE);