I'm trying to find a shortest path between 2 nodes using djikstra method but it keeps saying
SELECT seq, id1 AS node, id2 AS edge, cost FROM pgr_dijkstra('SELECT gid, source,target, ST_Length(geom2d) as cost FROM public.canada_rail_net', 1, 200, false, false); I'm very confused about this and can't find the problem
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ERROR: Error, query must return columns 'id', 'source', 'target' and 'cost'
this is my query:
SELECT seq, id1 AS node, id2 AS edge, cost FROM pgr_dijkstra('SELECT gid, source,target, ST_Length(geom2d) as cost FROM public.canada_rail_net', 1, 200, false, false); I'm very confused about this and can't find the problem
أكثر...