Changes between Version 15 and Version 16 of import layers postgis

Timestamp:

Jun 23, 2018 8:25:10 PM (7 years ago)

Author:

cedric

Comment:

--

import layers postgis

@@ -96 +96 @@
 
 
+To be able to explore the topology we could use pfafstetter
 
+{{{!#sql
+/*-----------------------------------------
+Function to get all segments downstream from one one in the same subbasin
+Problem when the subbasin changes it is difficult to go downstream
+-----------------------------------------*/
+CREATE OR REPLACE FUNCTION downstream_segments(_id text) 
+RETURNS TABLE(pfafcuen character varying(254), lngtramo_m numeric) AS
+$$
+BEGIN
+        RAISE NOTICE 'downstream segment for %', _id;    -- prints the selected segment
+        RETURN QUERY   
+             SELECT r.pfafcuen, r.lngtramo_m from  oria_a_rios_v2 r 
+                WHERE
+                 substring(_id::text,1,char_length(_id::text)-1)= 
+                   substring(r.pfafcuen::text,1,char_length(r.pfafcuen::text)-1) 
+                AND
+                 _id>r.pfafcuen
+                AND
+                 (r.pfafcuen::numeric % 2) = 1 
+               order by r.pfafcuen::numeric DESC;  -- even number               
+END
+$$
+  LANGUAGE plpgsql VOLATILE;
+select * from downstream_segments('10037146457'); 
+}}}
 
+this query returns the three odd nodes dowstream from '10037146457'
+
+||pfafcuen||    pfafrio||
+||10037146451||100371464||
+||10037146453||100371464||
+||10037146455||100371464||
+Problem from that step we need to go to another number
+
+10037146451 => 1003714643
+
+Before trying too much the following problem arises
+[[Image(source:eda/data/Docs/trac/sudoang/network_topology.PNG,400px)]]