Name

CG_Difference — Computes the geometric difference between two geometries

Synopsis

geometry CG_Difference( geometry geomA , geometry geomB );

Description

Computes the geometric difference between two geometries. The resulting geometry is a set of points that are present in geomA but not in geomB.

Performed by the SFCGAL module

[Note]

NOTE: this function returns a geometry.

Availability: 3.5.0

This method needs SFCGAL backend.

This function supports Triangles and Triangulated Irregular Network Surfaces (TIN).

Geometry Examples

Code
SELECT CG_Difference('POLYGON((0 0,0 1,1 1,1 0,0 0))'::geometry, 'LINESTRING(0 0,2 2)'::geometry);
Output
POLYGON((0 0,1 0,1 1,0 1,0 0))
Figure
Geometry figure for visual-cg-difference-01