Name
ST_M — Returns the M coordinate of a Point.
Synopsis
float ST_M(geometry a_point);
Description
Return the M coordinate of a Point, or NULL if not available. Input must be a Point.
![[Note]](../images/note.png)
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This is not (yet) part of the OGC spec, but is listed here to complete the point coordinate extractor function list. |
This method implements the OGC Simple Features
Implementation Specification for SQL 1.1.
This method implements the SQL/MM specification.
This function supports 3d and will not drop the z-index.
Examples
SELECT ST_M(ST_GeomFromEWKT('POINT(1 2 3 4)'));
st_m
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4
(1 row)