The ST_IsMeasured() function

The measure_test table is created with two columns: a SMALLINT column, gid, which uniquely identifies rows, and g1, an ST_Geometry column, which stores the ST_Point geometries:

CREATE TABLE measure_test (gid smallint,
                           g1  ST_Geometry);

The following INSERT statements insert two records into the measure_test table. The first record stores a point that does not have a measure, while the second record does have a measure value:

INSERT INTO measure_test VALUES(
    1,
    ST_PointFromText('point (10 10)',1000)
);

INSERT INTO measure_test VALUES(
    2,
    ST_PointFromText('point m (10.92 10.12 5)',1000)
);

The query lists the gid column and the results of the ST_IsMeasured() function. The ST_IsMeasured() function returns a 0 for the first row because the point does not have a measure; it returns a 1 for the second row because the point does have measures:

SELECT gid,ST_IsMeasured(g1) Has_measures 
   FROM measure_test;

   gid has_measures 

     1            f
     2            t