Returns the Well-Known Binary (WKB) representation of a geometry or geography object. The returned value does not include spatial reference identifier (SRID) metadata.
Syntax
bytea ST_AsBinary(geometry g1);
bytea ST_AsBinary(geometry g1, text NDRorXDR);
bytea ST_AsBinary(geography g1);
bytea ST_AsBinary(geography g1, text NDRorXDR);Parameters
| Parameter | Description |
|---|---|
g1 | The geometry or geography object to convert to WKB. |
NDRorXDR | The byte order of the output. Valid values: NDR (little-endian, default) and XDR (big-endian). |
Usage notes
The WKB specification does not include SRIDs. To get a WKB string that includes an SRID, use ST_AsEWKB.
Supported geometry types: circular strings, curves, polyhedral surfaces, triangles, triangulated irregular network (TIN) surfaces, and 3D objects.
Examples
Return WKB with the default little-endian byte order
SELECT ST_AsBinary(ST_GeomFromText('POLYGON((1 1,1 2,2 2,2 1,1 1))',4326));Output:
st_asbinary
---------------------------------------------------------------
\x01030000000100000005000000000000000000f03f000000000000f03f0
00000000000f03f0000000000000040000000000000004000000000000000
400000000000000040000000000000f03f000000000000f03f00000000000
0f03f
(1 row)Return WKB with big-endian byte order
SELECT ST_AsBinary(ST_GeomFromText('POLYGON((1 1,1 2,2 2,2 1,1 1))',4326),'XDR');Output:
st_asbinary
---------------------------------------------------------------
\x000000000300000001000000053ff00000000000003ff00000000000003
ff00000000000004000000000000000400000000000000040000000000000
0040000000000000003ff00000000000003ff00000000000003ff00000000
00000
(1 row)