ST_UnaryUnion

Introduction: This variant of ST_Union operates on a single geometry input. The input geometry can be a simple Geometry type, a MultiGeometry, or a GeometryCollection. The function calculates the geometric union across all components and elements within the provided geometry object.

Format: ST_UnaryUnion(geometry: Geometry)

Since: v1.6.1

SQL Example

SELECT ST_UnaryUnion(ST_GeomFromWKT('MULTIPOLYGON(((0 10,0 30,20 30,20 10,0 10)),((10 0,10 20,30 20,30 0,10 0)))'))

Output:

POLYGON ((10 0, 10 10, 0 10, 0 30, 20 30, 20 20, 30 20, 30 0, 10 0))