ST_AsEWKB

Introduction: Return the Extended Well-Known Binary representation of a geometry. EWKB is an extended version of WKB which includes the SRID of the geometry. The format originated in PostGIS but is supported by many GIS tools. If the geometry is lacking SRID a WKB format is produced.

Since v2.0.0, measured geometries retain M in the output, including those read from WKT; earlier versions dropped M. Z/M layouts declared in WKB are preserved for empty points, lines, and polygons and for NaN ordinates. Collections with no members have no stored coordinate layout and are written as XY.

Format: ST_AsEWKB (A: Geometry)

Return type: Binary

Since: v1.3.0

Example:

SELECT ST_AsEWKB(ST_SetSrid(ST_GeomFromWKT('POINT (1 1)'), 3021))

Output:

0101000020cd0b0000000000000000f03f000000000000f03f