Alias

Polygonize

Description

Creates a GeometryCollection made up of Polygons from a set of Geometries which contain lines that represents the Polygons edges. Lines must connect to one another at the endpoint.

Coordinate Dimensions

2D	3D	M

Spatial Standards Support

Examples

Array PostgreSQL

SELECT ST_AsEWKT(ST_Polygonize(
 Array[ST_GeomFromEWKT('LINESTRING (4 11, 4 4, 11 4, 11 11, 4 11)'),
       ST_GeomFromEWKT('LINESTRING (1 9, 1 5, 5 5, 5 9, 1 9)')]));

--Result
st_asewkt
--------------------------------------------------------------------------------
GEOMETRYCOLLECTION (POLYGON ((4 11, 11 11, 11 4, 4 4, 4 11)), POLYGON ((1 9, 5 9, 5 5, 1 5, 1 9)))
(1 row)

Array H2

SELECT ST_AsText(ST_Polygonize(st_accumagg(geom))) as myline from (select array_get(
(
st_geomfromtext('LINESTRING (4 11, 4 4, 11 4, 11 11, 4 11)'),
st_geomfromtext('LINESTRING (1 9, 1 5, 5 5, 5 9, 1 9)')
),x)::binary as geom from (select x from system_range(1,2) as foo) as tabla);
--Result
GEOMETRYCOLLECTION (POLYGON ((4 11, 11 11, 11 4, 4 4, 4 11)), POLYGON ((1 9, 5 9, 5 5, 1 5, 1 9)))

Aggregate

create table "lines"(id serial PRIMARY KEY);
SELECT AddGeometryColumn ('lines','GEOM',25830,'LINESTRING',2);

INSERT INTO "lines" ("GEOM") VALUES (ST_GeomfromEWKT('SRID=25830;LINESTRING (1 1, 1 4)'));
INSERT INTO "lines" ("GEOM") VALUES (ST_GeomfromEWKT('SRID=25830;LINESTRING (1 4, 2 4)'));
INSERT INTO "lines" ("GEOM") VALUES (ST_GeomfromEWKT('SRID=25830;LINESTRING (2 4, 2 1)'));
INSERT INTO "lines" ("GEOM") VALUES (ST_GeomfromEWKT('SRID=25830;LINESTRING (2 1, 1 1)'));
INSERT INTO "lines" ("GEOM") VALUES (ST_GeomfromEWKT('SRID=25830;LINESTRING (2 4, 3 4)'));
INSERT INTO "lines" ("GEOM") VALUES (ST_GeomfromEWKT('SRID=25830;LINESTRING (3 4, 3 1)'));
INSERT INTO "lines" ("GEOM") VALUES (ST_GeomfromEWKT('SRID=25830;LINESTRING (2 1, 3 1)'));

--PostgreSQL
select asewkt(ST_Polygonize("lines"."GEOM")) as polygonizer from "lines";
--H2
select asewkt(ST_PolygonizeAgg("lines"."GEOM")) as polygonizer from "lines";

SELECT DropGeometryTable ('lines');

--Result
POLYGONIZER  
SRID=25830;GEOMETRYCOLLECTION (POLYGON ((2 4, 2 1, 1 1, 1 4, 2 4)), POLYGON ((3 1, 2 1, 2 4, 3 4, 3 1)))

GeomA	ST_Polygonize(GeomA)
GeomA	ST_Polygonize(GeomA)

Related functions

ST_BuildArea