I was using the pgrouting plugin to display the shortestpath. I used the plugin as suggested by underdark to display the shortest path in qgis.
My source node is 283 and my target node is 172. When I used the pgrouting plugin to give me the shortest path I got one as attached in the screenshot.
However, when I queried the database of the graph which was generated by the tool osm2po. I found only one edge which was connected to node 283.
The result of the query is given in the figure below
My question is if you look at the results of the query, the edge is from node 279-283 and is one way as well with 283 being the target. Now since I used qgis to show the shortest path from 283-172. There is no starting from 283 as source. So my assumption was it shouldn't have shown any path. So I was wondering if there are some issues with the pgrouting plugin.
How come it gave me the shortest path when there is no edge with 283 as source? As I have explained there is only one edge connected to 283, but 283 is target and also the edge is one way from source to target.