ST_HasM — Checks if a geometry has an M (measure) dimension.
boolean ST_HasM(
geometry geom)
;
Checks if the input geometry has an M (measure) dimension and returns a boolean value. If the geometry has an M dimension, it returns true; otherwise, it returns false.
Geometry objects with an M dimension typically represent measurements or additional data associated with spatial features.
This function is useful for determining if a geometry includes measure information.
Availability: 3.5.0
This function supports 3d and will not drop the z-index.
This function supports M coordinates.
SELECT ST_HasM(ST_GeomFromText('POINTM(1 2 3)')); --result true
SELECT ST_HasM(ST_GeomFromText('LINESTRING(0 0, 1 1)')); --result false