ST_Force2D - Amazon Redshift
SyntaxArgumentsReturn typeExamples

ST_Force2D

ST_Force2D returns a 2D geometry of the input geometry. For 2D geometries, a copy of the input is returned. For 3DZ, 3DM, and 4D geometries, ST_Force2D projects the geometry to the xy-Cartesian plane. Empty points in the input geometry remain empty points in the output geometry.

Syntax

ST_Force2D(geom)

Arguments

geom

A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type.

Return type

GEOMETRY.

The spatial reference system identifier (SRID) value of the returned geometry is the SRID value of the input geometry.

If geom is null, then null is returned.

If geom is empty, then an empty geometry is returned.

Examples

The following SQL returns a 2D geometry from a 3DZ geometry. 

SELECT ST_AsEWKT(ST_Force2D(ST_GeomFromText('MULTIPOINT Z(0 1 2, EMPTY, 2 3 4, 5 6 7)')));

st_asewkt
-----------
  MULTIPOINT((0 1),EMPTY,(2 3),(5 6))