<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr">I am trying to script a function to return just the Linestring/MLinestring geom. </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr"><br></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr">My function will be able to iterate through the geom of polygons and mpolys and return the geom output (only) of st_dump(st_boundary(the_geom)).</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr"><br></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr">Problem is I am struggling with iterating through the 'path' array....and I don't seem to have a good sandbox way of capturing my errors (is there anything -- similar to SQLFIDDLE -- that works with the postgis ext?).</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr"><br></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr">EX Data:</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr"><br></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">CREATE TABLE poly_and_multipoly (</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> "id" SERIAL NOT NULL PRIMARY KEY,</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> "name" char(1) NOT NULL,</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> "the_geom" geometry NOT NULL</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">);</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">-- add data, A is a polygon, B is a multipolygon</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">INSERT INTO poly_and_multipoly (name, the_geom) VALUES (</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> 'A', 'POLYGON((7.7 3.8,7.7 5.8,9.0 5.8,7.7 3.8))'::geometry</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> ), (</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> 'B',</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> 'MULTIPOLYGON(((0 0,4 0,4 4,0 4,0 0),(1 1,2 1,2 2,1 2,1 1)), ((-1 -1,-1 -2,-2 -2,-2 -1,-1 -1)))'::geometry</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">);</div><div dir="ltr" class="" style="" id="yui_3_16_0_1_1434310020505_2627"><br class="" style=""></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr"><br></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr">Function:</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr"><br></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">CREATE OR REPLACE FUNCTION LinesFromPolygon2(polygon geometry) </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">RETURNS SETOF geometry_dump AS </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">$BODY$DECLARE </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> m integer;</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> g geometry;</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> p geometry_dump%ROWTYPE; </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">BEGIN</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">IF GeometryType($1) LIKE 'MULTI%' THEN </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> FOR m IN SELECT generate_series(1, ST_NumGeometries($1)) LOOP </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> p.path[1] := m; -- use to store Multipolygon number </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> g := ST_Dump(ST_Boundary($1, m));</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> RETURN NEXT p;</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> END LOOP;</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">ELSE -- It is not a MULTI- geometry </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> g := ST_Dump(ST_Boundary($1)); </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> END IF; </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> RETURN; </div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">END;$BODY$</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">LANGUAGE plpgsql ;</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr"><br></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr">ERROR:</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr"><br></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">SELECT id, name, LinesFromPolygon2(the_geom)</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""> FROM poly_and_multipoly;</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr"><br></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">ERROR: parse error - invalid geometry</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">HINT: "({" <-- parse error at position 2 within geometry</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">CONTEXT: PL/pgSQL function linesfrompolygon2(geometry) line 13 at assignment</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""><br class="" style=""></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">********** Error **********</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style=""><br class="" style=""></div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">ERROR: parse error - invalid geometry</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">SQL state: XX000</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">Hint: "({" <-- parse error at position 2 within geometry</div><div id="yui_3_16_0_1_1434310020505_2339" dir="ltr" class="" style="">Context: PL/pgSQL function linesfrompolygon2(geometry) line 13 at assignment</div><div id="yui_3_16_0_1_1434310020505_2339" class="" style=""> </div></div></body></html>