ST_AsBinary

Creates the Well-Known Binary (WKB) representation of a spatial object. Use this function when you need to convert an object to binary form for porting spatial data to or from other applications.

The Open Geospatial Consortium (OGC) defines the format of a WKB representation in the Simple Feature Access Part 1 - Common Architecture specification.

Behavior type

Syntax

ST_AsBinary( g )

Arguments

g

Spatial object for which you want the WKB, type GEOMETRY or GEOGRAPHY

Returns

LONG VARBINARY

Supported data types

Examples

The following example shows how to use ST_AsBinary.

Retrieve WKB and WKT representations:

=> CREATE TABLE locations (id INTEGER, name VARCHAR(100), geom1 GEOMETRY(800), geom2 GEOGRAPHY);
CREATE TABLE
=> COPY locations
    (id, geom1x FILLER LONG VARCHAR(800), geom1 AS ST_GeomFromText(geom1x), geom2x FILLER LONG VARCHAR (800),
     geom2 AS ST_GeographyFromText(geom2x))
   FROM stdin;
Enter data to be copied followed by a newline.
End with a backslash and a period on a line by itself.
>> 1|POINT(2 3)|
>> 2|LINESTRING(2 4,1 5)|
>> 3||POLYGON((-70.96 43.27,-70.67 42.95,-66.90 44.74,-67.81 46.08,-67.81 47.20,-69.22 47.43,-71.09 45.25,-70.96 43.27))
>> \.
=> SELECT id, ST_AsText(geom1),ST_AsText(geom2) FROM locations ORDER BY id ASC;
 id |       ST_AsText       |                 ST_AsText
----+-----------------------+---------------------------------------------
  1 | POINT (2 3)           |
  2 | LINESTRING (2 4, 1 5) |
  3 |                       | POLYGON ((-70.96 43.27, -70.67 42.95, -66.9 44.74, -67.81 46.08, -67.81 47.2, -69.22 47.43, -71.09 45.25, -70.96 43.27))
=> SELECT id, ST_AsBinary(geom1),ST_AsBinary(geom2) FROM locations ORDER BY id ASC;
.
.
.
(3 rows)

Calculate the length of a WKB using the Vertica SQL function LENGTH:

=> SELECT LENGTH(ST_AsBinary(St_GeomFromText('POLYGON ((-1 2, 0 3, 1 2,
                                                        0 1, -1 2))')));
 LENGTH
--------
     93
(1 row)

See also