Categories:: Geospatial Functions

ST_ASEWKB¶

Given a value of type GEOGRAPHY or GEOMETRY, return the binary representation of that value in EWKB (extended well-known binary) format.

See also:: ST_ASWKB

Syntax¶

ST_ASEWKB( <geography_or_geometry_expression> )

Arguments¶

geography_or_geometry_expression: The argument must be an expression of type GEOGRAPHY or GEOMETRY.

Returns¶

A value of type BINARY.

Usage Notes¶

For GEOGRAPHY objects, the SRID in the return value is always 4326. See the note on EWKT handling.
To return the output in WKB format, use ST_ASWKB instead.

Examples¶

GEOGRAPHY Examples¶

The following example demonstrates the ST_ASEWKB function. For the EWKB output, it is assumed that the BINARY_OUTPUT_FORMAT parameter is set to HEX (the default value for the parameter).

create table geospatial_table (id INTEGER, g GEOGRAPHY);
insert into geospatial_table values
    (1, 'POINT(-122.35 37.55)'), (2, 'LINESTRING(-124.20 42.00, -120.01 41.99)');

select st_asewkb(g)
    from geospatial_table
    order by id;
+--------------------------------------------------------------------------------------------+
| ST_ASEWKB(G)                                                                               |
|--------------------------------------------------------------------------------------------|
| 0101000020E61000006666666666965EC06666666666C64240                                         |
| 0102000020E610000002000000CDCCCCCCCC0C5FC00000000000004540713D0AD7A3005EC01F85EB51B8FE4440 |
+--------------------------------------------------------------------------------------------+

GEOMETRY Examples¶

The example below demonstrates how to use the ST_ASEWKB function. The example returns the EWKB representations of two geometries that have different SRIDs.

CREATE OR REPLACE TABLE geometry_table (g GEOMETRY);
INSERT INTO geometry_table VALUES
  ('SRID=4326;POINT(-122.35 37.55)'),
  ('SRID=0;LINESTRING(0.75 0.75, -10 20)');

SELECT ST_ASEWKB(g) FROM geometry_table;

+--------------------------------------------------------------------------------------------+
| ST_ASEWKB(G)                                                                               |
|--------------------------------------------------------------------------------------------|
| 0101000020E61000006666666666965EC06666666666C64240                                         |
| 01020000200000000002000000000000000000E83F000000000000E83F00000000000024C00000000000003440 |
+--------------------------------------------------------------------------------------------+