cdb_union_adgacent

pg/test/0.0.1/expected/05_cdb_union_adjacent_test.out

@@ -0,0 +1,5 @@
+st_astext
+------------------------------------------------
+POLYGON((1 0,0 0,0 1,0 2,1 2,1 1,2 1,2 0,1 0))
+POLYGON((4 1,4 0,3 0,3 1,3 2,4 2,4 1))
+(2 rows)

pg/test/0.0.1/sql/05_cdb_union_adjacent_test.sql

@@ -0,0 +1,9 @@
+\i test/fixtures/touching_polygons.sql
+
+WITH joined_polygons AS (
+  SELECT cdb_union_adjacent(the_geom) the_geom FROM touching_polygons
+),
+unnested_polygons as (
+  select unnest(joined_polygons.the_geom) the_geom from joined_polygons
+)
+select ST_ASTEXT(unnested_polygons.the_geom) from unnested_polygons;

pg/test/fixtures/touching_polygons.sql

@@ -0,0 +1,8 @@
+-- test table (polygons, some of which touch and some which dont)
+CREATE TABLE touching_polygons(cartodb_id integer, the_geom geometry);
+INSERT INTO  touching_polygons VALUES
+(1, ST_GeomFromText('POLYGON ((0 0, 1 0,1 1, 0 1, 0 0 ))')),
+(2, ST_GeomFromText('POLYGON ((1 0, 2 0, 2 1, 1 1, 1 0))')),
+(1, ST_GeomFromText('POLYGON ((0 1, 1 1,1 2, 0 2, 0 1 ))')),
+(4, ST_GeomFromText('POLYGON ((3 0, 4 0, 4 1, 3 1, 3 0))')),
+(5, ST_GeomFromText('POLYGON ((3 1, 4 1, 4 2, 3 2, 3 1))'));