Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198.
Existing Python UDFs will continue to function until June 30, 2026. For more information, see the
blog post
ST_M
ST_M returns the m coordinate of an input point.
Syntax
ST_M(point)
Arguments
- point
-
A
POINTvalue of data typeGEOMETRY.
Return type
DOUBLE PRECISION value of the m coordinate.
If point is null, then null is returned.
If point is a 2D or 3DZ point, then null is returned.
If point is the empty point, then null is returned.
If point is not a POINT, then an error is returned.
Examples
The following SQL returns the m coordinate of a point in a 3DM geometry.
SELECT ST_M(ST_GeomFromEWKT('POINT M (1 2 3)'));
st_m
-----------
3
The following SQL returns the m coordinate of a point in a 4D geometry.
SELECT ST_M(ST_GeomFromEWKT('POINT ZM (1 2 3 4)'));
st_m
-----------
4
