Alias

Collect

Description

Returns a geometry from the collection of others geometries. The resulting geometry can be GEOMETRYCOLLECTION or MULTI* type.

ST_Collect function can return invalid geometries A,B ST_Collect(A,B) returns Invalid Geometry SELECT ST_ISValid(a), ST_IsValidReason(a), ST_AsEWKT(a) FROM ST_Collect(ST_GeomFromText('POLYGON ((10 30, 10 70, 60 70, 60 30, 10 30))'), ST_GeomFromText('POLYGON((40 50, 40 80, 70 80, 70 50, 40 50))')) as a; --Result: st_isvalid | st_isvalidreason | ------------+------------------------------------------------------+ f | Self-intersection at or near point (60.0, 50.0, NaN) | st_asewkt --------------------------------------------------------------------------- MULTIPOLYGON (((10 30, 10 70, 60 70, 60 30, 10 30)), ((40 50, 40 80, 70 80, 70 50, 40 50))) (1 row)

Coordinate Dimensions

2D	3D	M

Spatial Standards Support

Examples

PostgreSQL

ST_Collect(geomA,geomB)

SELECT ST_AsEWKT(ST_Collect(ST_GeomFromText('POINT(5 5 10 8)'),
                            ST_GeomFromText('LINESTRING(0 0 10 8,1 1 1 1)')));
--Result
GEOMETRYCOLLECTION (POINT (5 5 10 8), LINESTRING (0 0 10 8, 1 1 1 1))

ST_Collect(geomArray)

SELECT AsEWKT(ST_Collect(Array[ST_MakePoint(0, 0), ST_MakePoint(10, 10),ST_MakePoint(15, 10)]));
                asewkt
--------------------------------------
 MULTIPOINT ((0 0), (10 10), (15 10))
(1 row)

ST_Collect(Aggregate)

This example creates a collection of points from a set of single points. 
The single points are stored in the gps_points table. 
The INSERT INTO statements that follow insert each one of the points geometries.

CREATE TABLE "gps_points"(id serial PRIMARY KEY);
SELECT AddGeometryColumn ('gps_points','geom',-1,'POINT',2);

INSERT INTO "gps_points" ("geom") VALUES (ST_GeomfromEWKT('SRID=-1;POINT(0 0)'));
INSERT INTO "gps_points" ("geom") VALUES (ST_GeomfromEWKT('SRID=-1;POINT(10 10)'));
INSERT INTO "gps_points" ("geom") VALUES (ST_GeomfromEWKT('SRID=-1;POINT(15 15)'));

SELECT asewkt(ST_Collect("gps_points"."geom")) as measures from "gps_points";
SELECT DropGeometryTable ('gps_points');

--Result
               measures
--------------------------------------
 MULTIPOINT ((0 0), (10 10), (15 15))

H2

ST_Collect(geomA,geomB)

SELECT ST_AsEWKT(ST_Collect(ST_GeomFromText('POINT(5 5 10 8)'),ST_GeomFromText('POINT(0 0 10 8)')));
--Result
MULTIPOINT ((5 5 10 8), (0 0 10 8))

ST_Collect(geomArray)

-- (1st Version)
SELECT ST_AsText(ST_Collect(st_accumagg(geom))) as mycollection from (SELECT array_get(
(
st_geomfromtext('POINT(0 0)'),
st_geomfromtext('POINT(10 10)'),
st_geomfromtext('POINT(15 15)')
),x)::binary as geom from (select x from system_range(1,3) as foo) as tabla);

--Result
MULTIPOINT ((0 0), (10 10), (15 15))

--(2nd Version)
SELECT ST_AsText(ST_Collect(st_accumagg(geom))) as myline
from
(SELECT ST_geomfromtext('LINESTRING(0 0,10 10)') as geom
union
SELECT ST_geomfromtext('LINESTRING(10 10,15 10)') 
union 
SELECT ST_geomfromtext('LINESTRING(15 10,20 20)') 
) as geom;

--Result
MULTILINESTRING ((10 10, 15 10), (15 10, 20 20), (0 0, 10 10))

ST_Collect(Aggregate)

CREATE TABLE "gps_points"(id serial PRIMARY KEY);
SELECT AddGeometryColumn ('gps_points','geom',-1,'POINT',2);

INSERT INTO "gps_points" ("geom") VALUES (ST_GeomfromEWKT('SRID=-1;POINT(0 0)'));
INSERT INTO "gps_points" ("geom") VALUES (ST_GeomfromEWKT('SRID=-1;POINT(10 10)'));
INSERT INTO "gps_points" ("geom") VALUES (ST_GeomfromEWKT('SRID=-1;POINT(15 15)'));

SELECT asewkt(ST_CollectAgg("gps_points"."geom")) as measures from "gps_points";
SELECT DropGeometryTable ('gps_points');

--Result
MEASURES  
MULTIPOINT ((0 0), (10 10), (15 15))

Related functions

ST_Dump