This question is, I think, very simple but I can't resolve it by myself.

I have a table 'cable' like this :

  id uuid primary_key,
  the_geom geometry(LineString, 2154)

And another table let's call it partpoint

CREATE TABLE partpoint (
  id uuid primary key,
  the_geom geometry(Point, 2154)

I want to know if, for a specific partpoint, this partpoint is part of linestring in the cable table. The first request was :

FROM cable 
                  (SELECT the_geom 
                   FROM partpoint 
                   WHERE id=<anUuid>))

But this does not work :-( Do I need to loop over all the table ? (with a for loop).

  • 1
    Show a little of each of your data points? Edit your question to add the results of SELECT id, AsEWKT(the_geom) FROM cable LIMIT 5 and SELECT id, AsEWKT(the_geom) FROM partpoint LIMIT 5. At a guess, you need to handle real number tolerances, but its hard to say without seeing the data. – BradHards Jul 10 '17 at 10:39
  • You should remove your edit and instead post it as an answer :) – Joseph Jul 10 '17 at 12:07

Find it ! I didn't know at that time that you can join spatially on a table. So the resulting query is :

 FROM partpoint pp 
 JOIN cable c ON (ST_contains(the_geom, pp.the_geom) 
 WHERE ST_CONTAINS(c.the_geom, 
                  (SELECT the_geom 
                   FROM partpoint 
                   WHERE id=<anUuid>))
| improve this answer | |
  • Your WHERE clause is not necessary. You can just add this: WHERE pp.id=<anUuid> OR JOIN (SELECT the_geom FROM partpoint WHERE id=<anUuid>) ON [...] – pLumo Jul 10 '17 at 14:36

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