ST_RemovePoint - Amazon Redshift
SyntaxArgumentsReturn typeExamples

ST_RemovePoint

ST_RemovePoint returns a linestring geometry that has the point of the input geometry at an index position removed.

The index is zero-based. The spatial reference system identifier (SRID) of the result is the same as the input geometry. The dimension of the returned geometry is the same as that of the input geometry.

Syntax

ST_RemovePoint(geom, index)

Arguments

geom

A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type. The subtype must be LINESTRING.

index

A value of data type INTEGER that represents the position of a zero-based index.

Return type

GEOMETRY

If geom or index is null, then null is returned.

If geom is not subtype LINESTRING, then an error is returned.

If index is out of range, then an error is returned. Valid values for the index position are between 0 and ST_NumPoints(geom) minus 1.

Examples

The following SQL removes the last point in a linestring. 

WITH tmp(g) AS (SELECT ST_GeomFromText('LINESTRING(0 0,10 0,10 10,5 5,0 5)',4326))
SELECT ST_AsEWKT(ST_RemovePoint(g, ST_NumPoints(g) - 1)) FROM tmp;

   st_asewkt
-----------------------------------------
 SRID=4326;LINESTRING(0 0,10 0,10 10,5 5)