ST_AsBinary — Return the Well-Known Binary (WKB) representation of the geometry/geography without SRID meta data.
bytea ST_AsBinary(geometry  g1);
bytea ST_AsBinary(geography  g1);
bytea ST_AsBinary(geometry  g1, text NDR_or_XDR);
Returns the Well-Known Binary representation of the geometry. There are 2 variants of the function. The first variant takes no endian encoding paramater and defaults to little endian. The second variant takes a second argument denoting the encoding - using little-endian ('NDR') or big-endian ('XDR') encoding.
This is useful in binary cursors to pull data out of the database without converting it to a string representation.
| ![[Note]](images/note.png) | |
| The WKB spec does not include the SRID. To get the OGC WKB with SRID format use ST_AsEWKB | 
| ![[Note]](images/note.png) | |
| ST_AsBinary is the reverse of ST_GeomFromWKB for geometry. Use ST_GeomFromWKB to convert to a postgis geometry from ST_AsBinary representation. | 
Availability: 1.5.0 geography support was introduced.
 This method implements the OpenGIS Simple Features
 Implementation Specification for SQL 1.1. s2.1.1.1
 This method implements the OpenGIS Simple Features
 Implementation Specification for SQL 1.1. s2.1.1.1
 This method implements the SQL/MM specification. SQL-MM 3: 5.1.37
 This method implements the SQL/MM specification. SQL-MM 3: 5.1.37
 This method supports Circular Strings and Curves
 This method supports Circular Strings and Curves
SELECT ST_AsBinary(ST_GeomFromText('POLYGON((0 0,0 1,1 1,1 0,0 0))',4326));
		   st_asbinary
--------------------------------
\001\003\000\000\000\001\000\000\000\005
\000\000\000\000\000\000\000\000\000\000
\000\000\000\000\000\000\000\000\000\000
\000\000\000\000\000\000\000\000\000\000
\000\000\000\360?\000\000\000\000\000\000
\360?\000\000\000\000\000\000\360?\000\000
\000\000\000\000\360?\000\000\000\000\000
\000\000\000\000\000\000\000\000\000\000\000
\000\000\000\000\000\000\000\000
(1 row)SELECT ST_AsBinary(ST_GeomFromText('POLYGON((0 0,0 1,1 1,1 0,0 0))',4326), 'XDR');
		   st_asbinary
--------------------------------
\000\000\000\000\003\000\000\000\001\000\000\000\005\000\000\000\000\000
\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000
\000?\360\000\000\000\000\000\000?\360\000\000\000\000\000\000?\360\000\000
\000\000\000\000?\360\000\000\000\000\000\000\000\000\000\000\000\000\000\000
\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000
(1 row)